Pianotech

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile. 

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful. 

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.  

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago. 

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed. 

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.  

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering. 


           



   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Hi Jim:
I had many similar experiences with a certain Chinese brand that our store was selling at the time. One model in particular, a 5 foot something, was particularly difficult to tune. Very tight pins, and of course the severe angles from the front bearings to agraffes. It would take me 3 hours to achieve a decent tuning. Most of the problems were near the top of the tenor section. I'd tune one note, then the next few, and already the first would be out again. Retune it, on and on, back and forth. Some of these Chinese pianos with identical plates and different names, are very difficult to tune. I used Protek to attempt to help the rendering, but it had minimal effect. Also, using the usual pitch raising protocol doesn't seem to work. If you tune with a good amount of overpull, look out! You'll be fighting it while you try to lower it again. Better results were obtained by pulling to pitch, and if necessary, go over it again.
Somehow I only have a couple of these in my clientele. I dread tuning them.
Paul McCloud
San Diego

________________________________________________________________________

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this. Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass s used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present. I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor- 30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 30mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for .5mm). Termination angle reasonable, 12deg. wide 1/4" diameter counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing, but it can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Reply to Group Online View Thread Recommend Forward Mark as Inappropriate


To change your subscriptions, go to My Subscriptions . To unsubscribe from this community discussion, go to Unsubscribe .


Original Message------

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile. 

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful. 

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.  

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago. 

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 30mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for .5mm). Termination angle reasonable, 12deg. wide 1/4" diameter counterbearing bar. 35mm dense felt highly compressed. 

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.  

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering. 


           



   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Right...this is a "Hallet&Davisfinegermancraftsmanshipmadeinchina" . I have no idea who made this, as no one is owning up to it.  I only have one more of these in my clientele, and try to tune it as little as possible. Another, a Samick, 5ft'er, after I tuned that horrible thing, on the way home I could not stop repeating the word "horrible-horrible-horrible" the entire 25 minute ride home...did I mention horrible? I will not be returning to tune that beast.

Interesting thing is, the problems that created this horribleness, are not hard to fix in a factory, before stringing. The termination angle is a plate design issue. However, in this case, even forgoing plate grinding, simply using an 1/16" radius bar, would both have reduced the termination angle to the low 20 deg's, and reduced the length of string in contact with that brass by 50%. Eliminating the felt would actually have saved both material and felt installation costs.  I may, in the course of messing with this, reduce the counter-bearing bar as an intermediate test to see what rendering improvement that buys. Final plan is to grind and use co-polymer.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-27-2018 11:44
From: Paul McCloud
Subject: High Friction Front String Bearing

Hi Jim:
I had many similar experiences with a certain Chinese brand that our store was selling at the time. One model in particular, a 5 foot something, was particularly difficult to tune. Very tight pins, and of course the severe angles from the front bearings to agraffes. It would take me 3 hours to achieve a decent tuning. Most of the problems were near the top of the tenor section. I'd tune one note, then the next few, and already the first would be out again. Retune it, on and on, back and forth. Some of these Chinese pianos with identical plates and different names, are very difficult to tune. I used Protek to attempt to help the rendering, but it had minimal effect. Also, using the usual pitch raising protocol doesn't seem to work. If you tune with a good amount of overpull, look out! You'll be fighting it while you try to lower it again. Better results were obtained by pulling to pitch, and if necessary, go over it again.
Somehow I only have a couple of these in my clientele. I dread tuning them.
Paul McCloud
San Diego

________________________________________________________________________

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this. Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass s used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present. I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor- 30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 30mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for .5mm). Termination angle reasonable, 12deg. wide 1/4" diameter counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing, but it can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Reply to Group Online View Thread Recommend Forward Mark as Inappropriate


To change your subscriptions, go to My Subscriptions . To unsubscribe from this community discussion, go to Unsubscribe .


Original Message------

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 30mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for .5mm). Termination angle reasonable, 12deg. wide 1/4" diameter counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

I had good results taming a quite rambunctious Baldwin SD-10's two capo sections by slacking the wire, pulling it out of the long curved counterbearing grooves, and laying graphite from a 6B pencil into them. It's possible also that by slacking the wire that far, thereby moving a little around the hitch pin, the flattened and tightly bent places on the wire were moved away from the bearing surfaces.

------------------------------
Susan Kline
Philomath, Oregon
------------------------------

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Yes, I was about to suggest the possibility of improvement "simply" with restringing. The specific type of wire used on these Asian pianos can be such that the bends are permanent once they set in, and not subject to change. 

Jim,

Have you had any opportunity to replace a wire on this thing with better wire and notice any difference? 

Pwg

------------------------------
Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com
------------------------------

Original Message:
Sent: 05-27-2018 13:38
From: Susan Kline
Subject: High Friction Front String Bearing

I had good results taming a quite rambunctious Baldwin SD-10's two capo sections by slacking the wire, pulling it out of the long curved counterbearing grooves, and laying graphite from a 6B pencil into them. It's possible also that by slacking the wire that far, thereby moving a little around the hitch pin, the flattened and tightly bent places on the wire were moved away from the bearing surfaces.

------------------------------
Susan Kline
Philomath, Oregon

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

I have changed out wire only in a Yamaha GP-1, which is right up (or down)there with these horrible pianos. There was some tonal improvement, but the instability remains. This GP-1 was a living room job, so I did not mess with front segment issues.

My take is that instability, or poor rendering, is a serious "tonal" problem. It needs to be corrected in order to get any sense of what the piano's structure has to offer, tonally. If you cannot tune the piano with precision, it has to, by definition, sound bad. Bad unisons and their attacks will be strident, mimicking lousy voicing. Said another way, a fine Fazioli that is way out of tune sounds as bad as a bottom feeder grand that is way out of tune.    

I will be re-scaling with Paullelo, after fixing the rendering. Also, I may float the bass or diaphram the low end a bit. Its also getting some Bacons on WNG shanks. I am really interested to see what is possible given the basic structure, and some custom work.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-27-2018 18:17
From: Peter Grey
Subject: High Friction Front String Bearing

Yes, I was about to suggest the possibility of improvement "simply" with restringing. The specific type of wire used on these Asian pianos can be such that the bends are permanent once they set in, and not subject to change.

Jim,

Have you had any opportunity to replace a wire on this thing with better wire and notice any difference?

Pwg

------------------------------
Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com

Original Message:
Sent: 05-27-2018 13:38
From: Susan Kline
Subject: High Friction Front String Bearing

I had good results taming a quite rambunctious Baldwin SD-10's two capo sections by slacking the wire, pulling it out of the long curved counterbearing grooves, and laying graphite from a 6B pencil into them. It's possible also that by slacking the wire that far, thereby moving a little around the hitch pin, the flattened and tightly bent places on the wire were moved away from the bearing surfaces.

------------------------------
Susan Kline
Philomath, Oregon

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Jim

I'm sure that whatever you do will improve the piano. But how is the customer with all of this? Are they willing to have you do all this work, instead of perhaps buying another piano for just a little more money?

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Original Message:
Sent: 05-27-2018 21:52
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I have changed out wire only in a Yamaha GP-1, which is right up (or down)there with these horrible pianos. There was some tonal improvement, but the instability remains. This GP-1 was a living room job, so I did not mess with front segment issues.

My take is that instability, or poor rendering, is a serious "tonal" problem. It needs to be corrected in order to get any sense of what the piano's structure has to offer, tonally. If you cannot tune the piano with precision, it has to, by definition, sound bad. Bad unisons and their attacks will be strident, mimicking lousy voicing. Said another way, a fine Fazioli that is way out of tune sounds as bad as a bottom feeder grand that is way out of tune.

I will be re-scaling with Paullelo, after fixing the rendering. Also, I may float the bass or diaphram the low end a bit. Its also getting some Bacons on WNG shanks. I am really interested to see what is possible given the basic structure, and some custom work.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-27-2018 18:17
From: Peter Grey
Subject: High Friction Front String Bearing

Yes, I was about to suggest the possibility of improvement "simply" with restringing. The specific type of wire used on these Asian pianos can be such that the bends are permanent once they set in, and not subject to change.

Jim,

Have you had any opportunity to replace a wire on this thing with better wire and notice any difference?

Pwg

------------------------------
Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com

Original Message:
Sent: 05-27-2018 13:38
From: Susan Kline
Subject: High Friction Front String Bearing

I had good results taming a quite rambunctious Baldwin SD-10's two capo sections by slacking the wire, pulling it out of the long curved counterbearing grooves, and laying graphite from a 6B pencil into them. It's possible also that by slacking the wire that far, thereby moving a little around the hitch pin, the flattened and tightly bent places on the wire were moved away from the bearing surfaces.

------------------------------
Susan Kline
Philomath, Oregon

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Wim, Hot Lava, Blees wrote:

"I'm sure that whatever you do will improve the piano. But how is the customer with all of this? Are they willing to have you do all this work, instead of perhaps buying another piano for just a little more money?"

Wim - Jim started his post with: "I picked up....." I think that means he bought it. So, his toy.

------------------------------
Terry Farrell
Farrell Piano Service, Inc.
Brandon, Florida
terry@farrellpiano.com
813-684-3505
------------------------------

Original Message:
Sent: 05-27-2018 23:58
From: Willem Blees
Subject: High Friction Front String Bearing

Jim

I'm sure that whatever you do will improve the piano. But how is the customer with all of this? Are they willing to have you do all this work, instead of perhaps buying another piano for just a little more money?

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789

Original Message:
Sent: 05-27-2018 21:52
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I have changed out wire only in a Yamaha GP-1, which is right up (or down)there with these horrible pianos. There was some tonal improvement, but the instability remains. This GP-1 was a living room job, so I did not mess with front segment issues.

My take is that instability, or poor rendering, is a serious "tonal" problem. It needs to be corrected in order to get any sense of what the piano's structure has to offer, tonally. If you cannot tune the piano with precision, it has to, by definition, sound bad. Bad unisons and their attacks will be strident, mimicking lousy voicing. Said another way, a fine Fazioli that is way out of tune sounds as bad as a bottom feeder grand that is way out of tune.

I will be re-scaling with Paullelo, after fixing the rendering. Also, I may float the bass or diaphram the low end a bit. Its also getting some Bacons on WNG shanks. I am really interested to see what is possible given the basic structure, and some custom work.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-27-2018 18:17
From: Peter Grey
Subject: High Friction Front String Bearing

Yes, I was about to suggest the possibility of improvement "simply" with restringing. The specific type of wire used on these Asian pianos can be such that the bends are permanent once they set in, and not subject to change.

Jim,

Have you had any opportunity to replace a wire on this thing with better wire and notice any difference?

Pwg

------------------------------
Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com

Original Message:
Sent: 05-27-2018 13:38
From: Susan Kline
Subject: High Friction Front String Bearing

I had good results taming a quite rambunctious Baldwin SD-10's two capo sections by slacking the wire, pulling it out of the long curved counterbearing grooves, and laying graphite from a 6B pencil into them. It's possible also that by slacking the wire that far, thereby moving a little around the hitch pin, the flattened and tightly bent places on the wire were moved away from the bearing surfaces.

------------------------------
Susan Kline
Philomath, Oregon

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170
------------------------------

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.  



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

JIm wrote:
"I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating."

Jim, could you please elaborate on this? What are your goals in doing this, and how do you achieve them?

Thanks,

Alan

------------------------------
Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483
------------------------------

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Alan,

I got the agraffe re-profiling from Ed Mcmorrow. Its simply to relieve the profile outside of the actual hole, so string excursion does not contact  the agraffe anywhere other than the termination.  No polishing or anything like that happens. It takes about an hour to set up and do this re-profiling.

Using a standard 135 deg included angle stub length drill, "nub" the bit. "Nubbing"  is just touching the two cutting points of the bit to a grinding wheel, just enough to remove the sharp cutting edge. If you don't "nub" the bit, the bit will grab and destroy the hole.

Hand hold the agraffe to a metal surface clamped to the drill press table. Set the drill press depth so, when both sides are reamed, 1mm land is left inside the agraffe hole.  The size of the bit matches the diameter of the profiled hole in the agraffe at the outside surface of the agraffe. So the reaming leaves the maximum amount of material that was removed in the original profiling at its original maximum diameter, and the 135 included angle of the drill bit widens the relief surrounding the original drilled hole. This lets the string self machine the brass, without the possibility of the string contacting the agraffe at a second point outside the actual termination hole.  The hole itself it not re-profiled.   

Ed,

good thought...I will check this when I re-profile the agraffes.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-28-2018 08:58
From: Alan Eder
Subject: High Friction Front String Bearing

JIm wrote:
"I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating."

Jim, could you please elaborate on this? What are your goals in doing this, and how do you achieve them?

Thanks,

Alan

------------------------------
Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Some low end Chinese pianos had rubber O rings under the agraffes to make alignment quick and easy.
I can't speak to the acoustic effects.

------------------------------
Ed Sutton
ed440@me.com
(980) 254-7413
------------------------------

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

I hope so. Not here in Hawaii, though. I just sold a 6' Yamaha, restrung, new hammers, and it took me several weeks to get only $5700 for it.  


------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

It depends on whether you have vision or not. One first commits oneself to make the instrument exceptional for that price range. This involves more than purchasing a set of hammers and strings. Then one learns how to market one's work, not just a patched up brand name product, but re-brand highlighting the artisanship and the artisan it takes to create said musically rewarding, but affordable instrument.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-28-2018 13:43
From: Willem Blees
Subject: High Friction Front String Bearing

, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

I hope so. Not here in Hawaii, though. I just sold a 6' Yamaha, restrung, new hammers, and it took me several weeks to get only $5700 for it.


------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Vision or not, it helps to have a much larger audience to choose from. Honolulu, on the island of Oahu, has less than 1 million people. (Even the Yamaha wound up going to another island). And basically, the piano market is very small. 

I'm sure you'll be able to sell your piano shortly after getting it rebuilt. Good luck, and have fun with your toy. lol

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Original Message:
Sent: 05-28-2018 14:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

It depends on whether you have vision or not. One first commits oneself to make the instrument exceptional for that price range. This involves more than purchasing a set of hammers and strings. Then one learns how to market one's work, not just a patched up brand name product, but re-brand highlighting the artisanship and the artisan it takes to create said musically rewarding, but affordable instrument.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 13:43
From: Willem Blees
Subject: High Friction Front String Bearing

, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

I hope so. Not here in Hawaii, though. I just sold a 6' Yamaha, restrung, new hammers, and it took me several weeks to get only $5700 for it.


------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Jim, 

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170
------------------------------

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Blaine,

Does one need to remove the string to coat the actual contact surface?

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Mr. Ialeggio,
I've had good success for years (20+) using Clear McLube on the capo and the front duplexes. I also routinely paint it ( I'm averse to spraying lubricants ) onto the understring felt. The version I use is called Sailcote and is available at marine supply stores. When I spoke with the fellow at McGee Industries who's responsible for all things McLube he told me that it is the same stuff as 1725 just with a different carrier mix that had to pass Coast Guard muster. Given your well publicized issues with V.O.C.'s be sure to take the usual precautions.You do have to at least move the string out of the way to apply it. Another issue may be that the wire used in China was plated and the plating is causing rendering problems. In a recent conversation I had with James Arledge he asserted that Mapes International Gold wire is plated and that it can cause similar trouble. I'd also check closely to see if the Brass is clear coated with something that is inhibiting it's natural self lubricating properties.

------------------------------
Karl Roeder
Pompano Beach FL
------------------------------

Original Message:
Sent: 05-29-2018 07:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Does one need to remove the string to coat the actual contact surface?

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Karl,

The brass is plated, similar to the way US local hardware stores brass plate solid brass. Its plated, because its a quick way to get a "polished" finish effect. The brass had a groove worn through the plating into it the solid stock. 

I had a conversation, a while ago, with the guy who was making Pure Sound Wire(forgot his name). As we talked about Pure Sound's brittleness, he mentioned that he always put bearing grease, as in car bearing grease on any string bearing. Seemed like a good idea, but  easy to get all over the place. I never tried it, preferring geometry and appropriate materials to do their fine little trick.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-29-2018 21:23
From: Karl Roeder
Subject: High Friction Front String Bearing

Mr. Ialeggio,
I've had good success for years (20+) using Clear McLube on the capo and the front duplexes. I also routinely paint it ( I'm averse to spraying lubricants ) onto the understring felt. The version I use is called Sailcote and is available at marine supply stores. When I spoke with the fellow at McGee Industries who's responsible for all things McLube he told me that it is the same stuff as 1725 just with a different carrier mix that had to pass Coast Guard muster. Given your well publicized issues with V.O.C.'s be sure to take the usual precautions.You do have to at least move the string out of the way to apply it. Another issue may be that the wire used in China was plated and the plating is causing rendering problems. In a recent conversation I had with James Arledge he asserted that Mapes International Gold wire is plated and that it can cause similar trouble. I'd also check closely to see if the Brass is clear coated with something that is inhibiting it's natural self lubricating properties.

------------------------------
Karl Roeder
Pompano Beach FL

Original Message:
Sent: 05-29-2018 07:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Does one need to remove the string to coat the actual contact surface?

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Thin DAG with alcohol and apply with a  small paintbrush to the string contact point at the agraffe or the speaking length of the treble string at the capo bar.  Raising the pitch should pull graphite into the contact point.

Couldn't hurt (unless you spill DAG).

------------------------------
Blaine Hebert
Duarte CA
626-795-5170
------------------------------

Original Message:
Sent: 05-29-2018 07:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Does one need to remove the string to coat the actual contact surface?

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Blaine,

Tried the Dag, pic attached.  Middle strings of two unisons removed from pin, and Dag applied to the actual contact surface. 1-Dag on counter-bearing bar and agraffe, 2 Dag only on counterbearing bar, 3 no Dag, but lowered the string 1/2 turn as I did with the Dag unisons to remove the beckets from the pins. #3 to make sure the lowering of the string was not delivering the entire result for all samples.

Inconclusive.

1- dag/agraffe & counterbearing bar-  behaved normally. SL responded to flexing of the pin, in a clear read-able fashion (previously no response was had from any attempts to move the string over the bearings) 
2-dag/counterbearing bar only- same normal behavior as #1
3-no dag, but string lowered 1/2 turn and returned to pitch- Improvement from the previous no movement until 1/8 CCW turn. Still sluggish with a somewhat obscure read of the front segment tension.

As Susan mentioned, just moving the string helps, at least for these ten minutes. I can see the Dag on #1-2 being ground off, with use. This is where co-polymer shines, because its lubricity doesn't wear off. It is interesting to see that the 30 deg termination angle can be made to work with lubrication, but why mess with mother nature, when the angle can be reduced. But as a site fix, the dag might work, if the client ponies up to allow you to let the tension down.

It is also interesting regarding the felt.  #1 had the dense compacted felt secondary bearing and #2 had no felt contact at all. Both functioned normally and as identically as I could discern with this simple test.





  
   ​​​​​​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

oops wrong attachment, and site does not allow editing attachments, I don't think.

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-29-2018 21:30
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Tried the Dag, pic attached.  Middle strings of two unisons removed from pin, and Dag applied to the actual contact surface. 1-Dag on counter-bearing bar and agraffe, 2 Dag only on counterbearing bar, 3 no Dag, but lowered the string 1/2 turn as I did with the Dag unisons to remove the beckets from the pins. #3 to make sure the lowering of the string was not delivering the entire result for all samples.

Inconclusive.

1- dag/agraffe & counterbearing bar-  behaved normally. SL responded to flexing of the pin, in a clear read-able fashion (previously no response was had from any attempts to move the string over the bearings)
2-dag/counterbearing bar only- same normal behavior as #1
3-no dag, but string lowered 1/2 turn and returned to pitch- Improvement from the previous no movement until 1/8 CCW turn. Still sluggish with a somewhat obscure read of the front segment tension.

As Susan mentioned, just moving the string helps, at least for these ten minutes. I can see the Dag on #1-2 being ground off, with use. This is where co-polymer shines, because its lubricity doesn't wear off. It is interesting to see that the 30 deg termination angle can be made to work with lubrication, but why mess with mother nature, when the angle can be reduced. But as a site fix, the dag might work, if the client ponies up to allow you to let the tension down.

It is also interesting regarding the felt.  #1 had the dense compacted felt secondary bearing and #2 had no felt contact at all. Both functioned normally and as identically as I could discern with this simple test.






   ​​​​​​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

I am only working with theory here, but very high pressure contacts like steel to steel friction points (not roller bearings) require lubricants that will stand up to the very high pressure at the tiny contact point.  Graphite has carbon to carbon bonds, the strongest known, and can stand up to very high pressures.  Molybdenum disulfide and perhaps lead might also work (https://en.wikipedia.org/wiki/Molybdenum_disulfide#Lubricant).

DAG is quite messy, but in a situation like this it might be well worth the appearance to avoid a restringing (which might NOT work).


------------------------------
Blaine Hebert
Duarte CA
626-795-5170
------------------------------

Original Message:
Sent: 05-29-2018 21:30
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Tried the Dag, pic attached.  Middle strings of two unisons removed from pin, and Dag applied to the actual contact surface. 1-Dag on counter-bearing bar and agraffe, 2 Dag only on counterbearing bar, 3 no Dag, but lowered the string 1/2 turn as I did with the Dag unisons to remove the beckets from the pins. #3 to make sure the lowering of the string was not delivering the entire result for all samples.

Inconclusive.

1- dag/agraffe & counterbearing bar-  behaved normally. SL responded to flexing of the pin, in a clear read-able fashion (previously no response was had from any attempts to move the string over the bearings)
2-dag/counterbearing bar only- same normal behavior as #1
3-no dag, but string lowered 1/2 turn and returned to pitch- Improvement from the previous no movement until 1/8 CCW turn. Still sluggish with a somewhat obscure read of the front segment tension.

As Susan mentioned, just moving the string helps, at least for these ten minutes. I can see the Dag on #1-2 being ground off, with use. This is where co-polymer shines, because its lubricity doesn't wear off. It is interesting to see that the 30 deg termination angle can be made to work with lubrication, but why mess with mother nature, when the angle can be reduced. But as a site fix, the dag might work, if the client ponies up to allow you to let the tension down.

It is also interesting regarding the felt.  #1 had the dense compacted felt secondary bearing and #2 had no felt contact at all. Both functioned normally and as identically as I could discern with this simple test.






   ​​​​​​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

I'm a little concerned when hearing about lubricity which doesn't wear off. There's such a thing as having rendering too easy, so that the slightest difference in tension between the segments, awfully easy from hard blows if the wire slides too easily, is instantly translated into changes in pitch. Tuning stability is awfully hard to achieve with a piano like this.

In a way, a piano which takes some effort to get the strings to render can be awfully stable once the work has been put into it. I know a 1971 Baldwin SD-10 which is like this. It can be a bear to tune if you don't pound on it and use a hammer technique it likes, but once you get it right it holds beautifully. Constantine Orbelian played the Schnittke Concerto with the Moscow Chamber Orchestra on this piano, and it coasted right through it (though I practically had a panic attack listening to the loud-dissonant and whispersoft-transparent episodes in it.)

Does "doesn't wear off" also mean "can't be taken off"?

------------------------------
Susan Kline
Philomath, Oregon
------------------------------

Original Message:
Sent: 05-30-2018 03:13
From: Blaine Hebert
Subject: High Friction Front String Bearing

I am only working with theory here, but very high pressure contacts like steel to steel friction points (not roller bearings) require lubricants that will stand up to the very high pressure at the tiny contact point.  Graphite has carbon to carbon bonds, the strongest known, and can stand up to very high pressures.  Molybdenum disulfide and perhaps lead might also work (https://en.wikipedia.org/wiki/Molybdenum_disulfide#Lubricant).

DAG is quite messy, but in a situation like this it might be well worth the appearance to avoid a restringing (which might NOT work).


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-29-2018 21:30
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Tried the Dag, pic attached.  Middle strings of two unisons removed from pin, and Dag applied to the actual contact surface. 1-Dag on counter-bearing bar and agraffe, 2 Dag only on counterbearing bar, 3 no Dag, but lowered the string 1/2 turn as I did with the Dag unisons to remove the beckets from the pins. #3 to make sure the lowering of the string was not delivering the entire result for all samples.

Inconclusive.

1- dag/agraffe & counterbearing bar-  behaved normally. SL responded to flexing of the pin, in a clear read-able fashion (previously no response was had from any attempts to move the string over the bearings)
2-dag/counterbearing bar only- same normal behavior as #1
3-no dag, but string lowered 1/2 turn and returned to pitch- Improvement from the previous no movement until 1/8 CCW turn. Still sluggish with a somewhat obscure read of the front segment tension.

As Susan mentioned, just moving the string helps, at least for these ten minutes. I can see the Dag on #1-2 being ground off, with use. This is where co-polymer shines, because its lubricity doesn't wear off. It is interesting to see that the 30 deg termination angle can be made to work with lubrication, but why mess with mother nature, when the angle can be reduced. But as a site fix, the dag might work, if the client ponies up to allow you to let the tension down.

It is also interesting regarding the felt.  #1 had the dense compacted felt secondary bearing and #2 had no felt contact at all. Both functioned normally and as identically as I could discern with this simple test.






   ​​​​​​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Susan,

I get your concern regarding rendering which presents no resistance at all. I just tuned a rebuild like this (not mine). It is extremely difficult to tune. Tight pins, no friction at all in the front segments, no pin bushings, and coils high off the plate. 

However, the point is to understand how the highly variable parameters each piano and each section within the piano can be combined and controlled when setting up the front segment conditions. When a high lubricity material like co-polymer is used, one takes into consideration termination angles, distance between termination and counter-bearing, width of co-polymer bearing, compressed felt or not, pin bushings or not, etc, as parameters to be combined, as per the conditions that piano exhibits. Combining the parameters with purpose, allows one to seek the sweet spot of enough friction, but not too much. The original setups may or may not be something to copy, especially as front segment bearings are an afterthought in most shops...as in, lets get this thing strung, rather than stopping and considering the problem before proceeding with the stringing.

This patient's tenor will work nicely with reduced but still elevated low 20 deg termination angles, 3/4" width of co-polymer, and probably a short span of dense felt.  If the termination angle was 12deg or less, I would not include the co-polymer at all, and probably try to just use under-string felt, depending on the shape of the plate. Small radius brass counter-bearing might be an option, but I'm kind of off on the brass counter-bearing these days, having seen many that were a real problem for friction.     

 


------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-30-2018 03:32
From: Susan Kline
Subject: High Friction Front String Bearing

I'm a little concerned when hearing about lubricity which doesn't wear off. There's such a thing as having rendering too easy, so that the slightest difference in tension between the segments, awfully easy from hard blows if the wire slides too easily, is instantly translated into changes in pitch. Tuning stability is awfully hard to achieve with a piano like this.

In a way, a piano which takes some effort to get the strings to render can be awfully stable once the work has been put into it. I know a 1971 Baldwin SD-10 which is like this. It can be a bear to tune if you don't pound on it and use a hammer technique it likes, but once you get it right it holds beautifully. Constantine Orbelian played the Schnittke Concerto with the Moscow Chamber Orchestra on this piano, and it coasted right through it (though I practically had a panic attack listening to the loud-dissonant and whispersoft-transparent episodes in it.)

Does "doesn't wear off" also mean "can't be taken off"?

------------------------------
Susan Kline
Philomath, Oregon

Original Message:
Sent: 05-30-2018 03:13
From: Blaine Hebert
Subject: High Friction Front String Bearing

I am only working with theory here, but very high pressure contacts like steel to steel friction points (not roller bearings) require lubricants that will stand up to the very high pressure at the tiny contact point.  Graphite has carbon to carbon bonds, the strongest known, and can stand up to very high pressures.  Molybdenum disulfide and perhaps lead might also work (https://en.wikipedia.org/wiki/Molybdenum_disulfide#Lubricant).

DAG is quite messy, but in a situation like this it might be well worth the appearance to avoid a restringing (which might NOT work).


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-29-2018 21:30
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Tried the Dag, pic attached.  Middle strings of two unisons removed from pin, and Dag applied to the actual contact surface. 1-Dag on counter-bearing bar and agraffe, 2 Dag only on counterbearing bar, 3 no Dag, but lowered the string 1/2 turn as I did with the Dag unisons to remove the beckets from the pins. #3 to make sure the lowering of the string was not delivering the entire result for all samples.

Inconclusive.

1- dag/agraffe & counterbearing bar-  behaved normally. SL responded to flexing of the pin, in a clear read-able fashion (previously no response was had from any attempts to move the string over the bearings)
2-dag/counterbearing bar only- same normal behavior as #1
3-no dag, but string lowered 1/2 turn and returned to pitch- Improvement from the previous no movement until 1/8 CCW turn. Still sluggish with a somewhat obscure read of the front segment tension.

As Susan mentioned, just moving the string helps, at least for these ten minutes. I can see the Dag on #1-2 being ground off, with use. This is where co-polymer shines, because its lubricity doesn't wear off. It is interesting to see that the 30 deg termination angle can be made to work with lubrication, but why mess with mother nature, when the angle can be reduced. But as a site fix, the dag might work, if the client ponies up to allow you to let the tension down.

It is also interesting regarding the felt.  #1 had the dense compacted felt secondary bearing and #2 had no felt contact at all. Both functioned normally and as identically as I could discern with this simple test.






   ​​​​​​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Good luck with your project, Jim. It does sound like fun.

That SD-10 is the one where I loaded the long counterbearing grooves with graphite. It still is a handful to tune, but much less aggravating than it used to be. I agree about rendering having a sweet spot with enough resistance but not too much. It's actually quite a wide sweet spot ...

------------------------------
Susan Kline
Philomath, Oregon
------------------------------

Original Message:
Sent: 05-30-2018 08:13
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Susan,

I get your concern regarding rendering which presents no resistance at all. I just tuned a rebuild like this (not mine). It is extremely difficult to tune. Tight pins, no friction at all in the front segments, no pin bushings, and coils high off the plate.

However, the point is to understand how the highly variable parameters each piano and each section within the piano can be combined and controlled when setting up the front segment conditions. When a high lubricity material like co-polymer is used, one takes into consideration termination angles, distance between termination and counter-bearing, width of co-polymer bearing, compressed felt or not, pin bushings or not, etc, as parameters to be combined, as per the conditions that piano exhibits. Combining the parameters with purpose, allows one to seek the sweet spot of enough friction, but not too much. The original setups may or may not be something to copy, especially as front segment bearings are an afterthought in most shops...as in, lets get this thing strung, rather than stopping and considering the problem before proceeding with the stringing.

This patient's tenor will work nicely with reduced but still elevated low 20 deg termination angles, 3/4" width of co-polymer, and probably a short span of dense felt.  If the termination angle was 12deg or less, I would not include the co-polymer at all, and probably try to just use under-string felt, depending on the shape of the plate. Small radius brass counter-bearing might be an option, but I'm kind of off on the brass counter-bearing these days, having seen many that were a real problem for friction.




------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-30-2018 03:32
From: Susan Kline
Subject: High Friction Front String Bearing

I'm a little concerned when hearing about lubricity which doesn't wear off. There's such a thing as having rendering too easy, so that the slightest difference in tension between the segments, awfully easy from hard blows if the wire slides too easily, is instantly translated into changes in pitch. Tuning stability is awfully hard to achieve with a piano like this.

In a way, a piano which takes some effort to get the strings to render can be awfully stable once the work has been put into it. I know a 1971 Baldwin SD-10 which is like this. It can be a bear to tune if you don't pound on it and use a hammer technique it likes, but once you get it right it holds beautifully. Constantine Orbelian played the Schnittke Concerto with the Moscow Chamber Orchestra on this piano, and it coasted right through it (though I practically had a panic attack listening to the loud-dissonant and whispersoft-transparent episodes in it.)

Does "doesn't wear off" also mean "can't be taken off"?

------------------------------
Susan Kline
Philomath, Oregon

Original Message:
Sent: 05-30-2018 03:13
From: Blaine Hebert
Subject: High Friction Front String Bearing

I am only working with theory here, but very high pressure contacts like steel to steel friction points (not roller bearings) require lubricants that will stand up to the very high pressure at the tiny contact point.  Graphite has carbon to carbon bonds, the strongest known, and can stand up to very high pressures.  Molybdenum disulfide and perhaps lead might also work (https://en.wikipedia.org/wiki/Molybdenum_disulfide#Lubricant).

DAG is quite messy, but in a situation like this it might be well worth the appearance to avoid a restringing (which might NOT work).


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-29-2018 21:30
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Tried the Dag, pic attached.  Middle strings of two unisons removed from pin, and Dag applied to the actual contact surface. 1-Dag on counter-bearing bar and agraffe, 2 Dag only on counterbearing bar, 3 no Dag, but lowered the string 1/2 turn as I did with the Dag unisons to remove the beckets from the pins. #3 to make sure the lowering of the string was not delivering the entire result for all samples.

Inconclusive.

1- dag/agraffe & counterbearing bar-  behaved normally. SL responded to flexing of the pin, in a clear read-able fashion (previously no response was had from any attempts to move the string over the bearings)
2-dag/counterbearing bar only- same normal behavior as #1
3-no dag, but string lowered 1/2 turn and returned to pitch- Improvement from the previous no movement until 1/8 CCW turn. Still sluggish with a somewhat obscure read of the front segment tension.

As Susan mentioned, just moving the string helps, at least for these ten minutes. I can see the Dag on #1-2 being ground off, with use. This is where co-polymer shines, because its lubricity doesn't wear off. It is interesting to see that the 30 deg termination angle can be made to work with lubrication, but why mess with mother nature, when the angle can be reduced. But as a site fix, the dag might work, if the client ponies up to allow you to let the tension down.

It is also interesting regarding the felt.  #1 had the dense compacted felt secondary bearing and #2 had no felt contact at all. Both functioned normally and as identically as I could discern with this simple test.






   ​​​​​​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-29-2018 02:57
From: Blaine Hebert
Subject: High Friction Front String Bearing

Jim,

Please try my suggestion of a thin, light graphite application (DAG) on the contact points of the capo bar and agraffes (try applying from the speaking side).  I am curious of how it would work...

------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-28-2018 08:43
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Yep Terry, my toy...and I'm greatly enjoying said toy. I picked it up because it was an excellent candidate not only to better understand the nastiness's (note the plural), but as a spec piano, a 6ft'er that sounds nice and has a nice touch, at $11-12k would be relatively easy to move.

<I am also suspicious of the brass or plating (gold?) on these Chinese agraffes. 

I have considered this, but did not know how to prove it.  But, before jumping to exotic reasons for this rendering behavior, the termination parameters I outlined are obvious, and well known physical impediments. Still...while its apart, I would mess with the alloy, if I knew how to quantify the material's makeup. I will re-profile the agraffes, as I usually do. That will leave only 1mm bearing inside the agraffe hole with potential plating. I don't ream the actual hole, but might enlarge it a couple of thousandths if I thought plating might be implicated. Problem with that would be that, in addition to fixing the termination conditions, I would be doing too many changes to know which change produced what result.



------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Blaine,

Graphite, as in Dag on the capo?

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Dag is kind of messy. If I want to use graphite somewhere like that, I just rub it with a 6B pencil. (Don't leave home without one.)

------------------------------
Susan Kline
Philomath, Oregon
------------------------------

Original Message:
Sent: 05-28-2018 08:44
From: Jim Ialeggio
Subject: High Friction Front String Bearing

Blaine,

Graphite, as in Dag on the capo?

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 05-28-2018 01:37
From: Blaine Hebert
Subject: High Friction Front String Bearing

Some of the rebuilds I am seeing from good local shops use graphite on the bearing points in the treble and I seldom have trouble with these pianos.

I have tried applying graphite in the past as a treatment on sticky pianos but it quickly gets too messy.  I still wonder if we should consider it as a good treatment.

If we apply a thin, light graphite application with a small paint brush and apply only to the contact points and perhaps at the beginning of the speaking length near agraffes we might get away without disfiguring customer's pianos and this could correct the problems.

Has anyone tried this?

I am also suspicious of the brass or plating (gold?) on these Chinese agraffes.  I have noticed old Steinway agraffes will occasionally stick or pop and I suspected the alloy.  Perhaps we are dealing with an alloy issue on many of these.


------------------------------
Blaine Hebert
Duarte CA
626-795-5170

Original Message:
Sent: 05-27-2018 09:56
From: Jim Ialeggio
Subject: High Friction Front String Bearing

I picked up a pretty horrible Chinese 6ft grand because I wanted to quantify some of the issues that made it un-tunable, and I know I can improve both its tune-ability and tonal profile.

I had condemned it a year ago, and told my client I would not service it any more without major work. Every time I attempted to tune it I hurt myself, the tuning was horrible, and utterly unstable. The problem was that one might be able to come up to pitch, but no settling down at all was allowed...ever. If I missed the mark and had to lower the string and start over, the uncertainty of the front segment tension then became completely unknown. I never actually came up with a workable scenario that was even remotely stable.

There has been much discussion on these lists about the effects of too much felt or too dense under-string felt creating friction problems. So I was on the lookout for this.  Also brass counter-bearing bars were discussed as having the potential to solve many front segment bearing problems. However, some of the worse rendering pianos I have met in the field had brass counter-bearings. So, having observed somewhat inconclusive and conflicting evidence when both felt and brass are used, in the field and in my shop, I have been trying to understand under what conditions felt or brass are helpful or not helpful.

So I am very interested in quantifying why this particular beast's rendering was so horrible. On-site, I had experimented with the felt parameter, removing felt under the bearing. It had achieved zero improvement, in at least in one of this piano's sections, so I was curious to look into this further, without the on-site time pressure to tune the beast, lick my wounds and run.

There are a number of string bearing parameters that effect the rendering of the string. The friendliness of the rendering will depend on how many of these parameters exist in a particular front segment, how the parameters are defined, and in what combination they are present.  I think I'll expand this into an article, adding other parameters to Del's excellent termination angle article of many moons ago.

pics of the patient attached

1-Entire tenor-  30deg termination angle, wide brass counter-bearing, 35mm wide felt, dense highly compressed, short 20mm segment between agraffe and brass counter-bearing, bushed pins. Rendering- It takes 1/8 of a turn CCW, delivered in 4 discrete downward movements of the pin, before any change in the SL happens at all, even if those discrete CCW pin movements are accompanied by jerks, slaps or pin flexing. Short of the 1/8 CCW rotation, change only happens with time...5-15 minutes.

Fix- given the termination angle, and the wide radius of the brass counterbearing, removing the dense felt is ineffectual...no change in behavior. The fix is to reduce the termination angle...grinding the plate as necessary. Given the plate design, the angle will still be a bit strong of the 12-15deg target. So, the counter-bearing will be co-polymer. Tiny amount of very fluffy felt behind the co-polymer. The 20mm segment between termination and counter-bearing is fine, and was not a factor in the poor rendering. If this length was longer as it is in many European grands, I would think about front segment differently.

2-alto capo- decently shaped v-bar. a little wide @ 1.5 mm but not as bad as many v-bars(I shoot for 0.5mm). Termination angle reasonable, 12deg. wide radius counterbearing bar. 35mm dense felt highly compressed.

Fix- termination angle acceptable. Capo not my ideal, but acceptable (in terms of rendering). Brass counter-bearing radius ended up being acceptable. Felt cut away entirely. In this case, as opposed to the tenor case, the felt was the problem. Removal of felt resulted in normal  friendly rendering.

One of the takeaways I have been noticing for some time, is that felt, even wide felt can be used to create friendly rendering as counter-bearing as in the case of Kawai RX series(very low termination angles, sweet rendering piano). Brass counter-bearing can also be used to create friendly rendering, assuming acceptable termination angles. Trouble begins when termination angles are too high as Del described. Trouble also begins when both brass, and felt are used as friction surfaces. If brass is to be used, then the felt must be non-compressed damping fluff only, not for string bearing. If felt is used as bearing, brass should not be added as a secondary counter-bearing to achieve take-off angles to the pin.

Co-polymer can be useful where termination angles are too high(only speaking of rendering here), or if a pin/string takeoff angle adjustment is required, and in other scenarios.

The use of co-polymer to improve pin/string take off angles will create a secondary bearing. It can do this more safely than brass or felt can. These days, though, I don't worry about the string takeoff angle much, actually. I have found that the makeup of the bearings, and avoiding secondary counter-bearing so important in achieving friendly rendering, that when push comes to shove, I have not found, at least in the angles I drill blocks at (usually 2-3 deg) that greater than 90 deg pin/string takeoff angle, is worth compromising the rendering for.

Many combinations of materials and angles have to be accounted for in setting up reasonable unto real nice rendering.






   ​

------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------