Pianotech

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

1.25" is a really large aftertouch!!

But when it comes to building a smooth and even touch, i find moving the capstans very low on the list of things to do. If all parts are original, you should be fine. If not you have to find where someone screwed up. After that, I'd focus on correct strike weight ( 10.5 -5g or less), then fix all friction, proper leading of the keys, and follow the mfgr's specs as to regulation. One of which is 47g DW across the keyboard.

-chris

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

1.25" is a really large aftertouch!!

But when it comes to building a smooth and even touch, i find moving the capstans very low on the list of things to do. If all parts are original, you should be fine. If not you have to find where someone screwed up. After that, I'd focus on correct strike weight ( 10.5 -5g or less), then fix all friction, proper leading of the keys, and follow the mfgr's specs as to regulation. One of which is 47g DW across the keyboard.

-chris

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com

Original Message:
Sent: 10-01-2023 04:02
From: David Love
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 09-30-2023 15:31
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com
------------------------------

So the first question is why are you moving it?  I routinely convert slanted capstans to vertical capstans especially when using square heel wippens so location is a decision that has to be made. But the key ratio choice depends on the overall action ratio goal which means you need to account for the knuckle placement as well as the capstan contact point on the wippen heel.  

I think this is a larger discussion that requires a review of the three levers, product of levers, general action ratio concepts, methods of measurement and assessment of what that means both for weight and regulation. In addition, we would need to review the particular problems unique to Steinway,  This is more than I can take on in this forum. It's not a simple answer. 

I would probably start with a review of the overall system. Mario Igrec's book "Pianos Inside and Out" has a chapter devoted to this. Nick Gravagne's program is nicely interactive, and David Stanwood  procedures and ideas will give you a guide for using weight and balance rather than distance to analyze piano action performance. 

The procedure to move capstans is not difficult. The why and where is a little more involved. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 10-01-2023 17:25
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com

Original Message:
Sent: 10-01-2023 04:02
From: David Love
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 09-30-2023 15:31
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com
------------------------------

David Love hit the nail on the head, more info is needed.  We offer free action ratio analysis if you fill out the web form at:

https://www.reyburn.com/geometry.html

Use the PDF that's linked on the page with pictures. With 30 minutes or measurements, fill out this form, I can give a good answer as to what's wrong if anything.  The directions say to use a straight key in the middle (like 21 or 27). But you can instead fill out the form twice, once for note 1 and 88 each. That is in fact how we design new keysets and actions.

The only issue with measuring keys with large doglegs such as 1 and 88 is you have to do it orthogonally. That is, using right angles for measuring the keys. You can't use a tape measure along the key, you need a large square to eliminate the key angle. If that's not clear I can send a picture.

-Dean

------------------------------
Dean Reyburn, RPT
Reyburn Pianoworks
Reyburn CyberTuner
1-616-498-9854
dean@reyburn.com
www.reyburnpianoworks.com
www.cybertuner.com
www.reyburntools.com
Facebook: www.facebook.com/dean.reyburn

Original Message:
Sent: 10-01-2023 21:13
From: David Love
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

So the first question is why are you moving it?  I routinely convert slanted capstans to vertical capstans especially when using square heel wippens so location is a decision that has to be made. But the key ratio choice depends on the overall action ratio goal which means you need to account for the knuckle placement as well as the capstan contact point on the wippen heel.  

I think this is a larger discussion that requires a review of the three levers, product of levers, general action ratio concepts, methods of measurement and assessment of what that means both for weight and regulation. In addition, we would need to review the particular problems unique to Steinway,  This is more than I can take on in this forum. It's not a simple answer. 

I would probably start with a review of the overall system. Mario Igrec's book "Pianos Inside and Out" has a chapter devoted to this. Nick Gravagne's program is nicely interactive, and David Stanwood  procedures and ideas will give you a guide for using weight and balance rather than distance to analyze piano action performance. 

The procedure to move capstans is not difficult. The why and where is a little more involved. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 10-01-2023 17:25
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com

Original Message:
Sent: 10-01-2023 04:02
From: David Love
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 09-30-2023 15:31
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com
------------------------------

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 09-30-2023 15:31
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com
------------------------------

Original Message:
Sent: 10-01-2023 17:25
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com

Original Message:
Sent: 10-01-2023 04:02
From: David Love
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 09-30-2023 15:31
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com
------------------------------

Thank you all for your comments. The action analysis tool I have been using is Nick Gravagne's AGP program and I have closely studied his Action Ratio series of articles in the Journal. I have also read and studied all materials of Stanwood's, Fandrich, and Igrec's methods. My findings of how much to move the capstan line agree with the results gotten from Gravagne's AGP program. The reason I want to move the capstan line is because I am now getting a blow distance of 41.5 to 43.5mm when dip and aftertouch are set correctly across six sample notes. It's too shallow of a blow distance. My goal is to have a 45 to 46mm blow distance.

I have made some progress with discovering the possible reasons for my original problem, which is a large difference in the amount I need to move the capstan position when the bass and tenor sections are compared to the treble section. After speaking to Will Truitt about this problem he suggested that I take the following measurements to assess any problems with the action.

1) Wippen center pin height, hammer shank pin height. (The action spread dimensions seem to be fine in this piano.)

2) Key measurements, front of key to balance pin and balance pin to capstan.

3) String height across the range of the piano

4) Hammer bore distance, from center of bore to top of the hammer, across the range of the piano.

From previous measurements I have taken I can say that the wippen and hammer flange pin heights may be off a bit. And then the string heights on this piano taper downward as you move to the treble section, that is the treble strings are closer to the bed of the piano than the bass and tenor strings. 

If the height of the action brackets are off I will shim the action and fix this. Also, if the hammer bores in the treble section were not properly done to match the varying string heights, this may be part of what is causing my problems with the capstan line. Hopefully doing all these action measurements will reveal the causes of the capstan position issue.

Once, the blow distance is where I want it, I will figure out the best hammer type and weight that sounds best with this piano. So far, I have gotten suggestions to try two types of Ronsen hammers, the Bacon felt and Weickert felt hammers. I'll try them both and see what sounds the best.

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com

Original Message:
Sent: 10-03-2023 13:04
From: John Pope
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Original Message:
Sent: 10-01-2023 17:25
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Thanks for your comments, everyone. Please excuse my ignorance and inexperience with some of these issues. This is the first time I am attempting to move a capstan line on a piano.

1) I may have inadvertently caused the capstan position to be different in the treble section by changing the way I bedded the action after I completed analyzing the bass and tenor capstan line. When I was analyzing the bass and tenor capstan line, I was bedding the action only in the rest position without pressing the sustain or shift pedal. Then, I changed the way I bedded the action (after doing some research on this subject), making sure the action was bedded in the rest position, then with the sustain pedal pressed, then the shift pedal pressed, and then the sustain and shift pedal pressed at the same time. To bed the action properly in all these positions, I had to turn down the action bolts a little more. This would definitely change the Dip on the keys and throw off my results.

So, what I will now do is to put the action back together, and bed it in all the positions, then take the action out of the piano, put it on a bench and measure the height of the hammer shank pin. Then I will deduct this from the string height to come up with the theoretical blow distance. (Thank you Peter)

2) On note 44 the distance from front of key to Balance pin is 238mm. Distance from Balance pin to capstan center is 115.24, which is a .48 ratio. Let's say that I move the capstan line back to 118mm, then the ration will be changed to a hair under .50, which is more desirable I believe. They way I am measuring the key is straight across from the balance pin to the front of the key (not the key top lip), and then from the balance pin straight across to the center line of the capstan. After doing that I will regulate the piano with a 10.1 dip and a 1.25 Aftertouch and see what my hammer blow distance comes to.

3) Right now, the existing capstan position is hitting the wippen cushion a little bit towards the front of the action, so there is some room there to move the capstan line and have it meet the wippen cushion more in the middle, which I believe is more optimal.

4) Sighting down the side of the action looking at balance pin position, I do see that the balance pin line is a bit wobbly and not completely straight. Do any of you ever bend an out of position balance pin to either toward the back or front of the action to get them more in line with the rest of the pins? Can doing this make any difference or is it a waste of time?

------------------------------
Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com

Original Message:
Sent: 10-01-2023 04:02
From: David Love
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

How are you going about determining the regulation specs vis the capstan line? Normally you would make that determination by establishing the key ratio as uniform on either end of the key set and striking a straight line using those two points. Or, you would establish a capstan position at the end keys (A0 and C88–both naturals btw) that is centered, or in a similar position, vis the wippen cushion.

It should be noted that both techniques can result in differences in action ratio at either end which will result in different regulation specs across the set since the AR determines the way the action regulates. Similarly, a uniform key ratio that positions the capstan at variance under the wippen cushion will also mean that the AR is not equal end to end because the wippen lever ratio will be altered. 

When establishing the new capstan position on an old Steinway I am always cognizant of weight as well as regulation specs and generally target a key ratio of .50-.52 (Starwood method) with a 17 mm knuckle. From there I then determine the optimum strike weight curve and accept the regulation it produces. Rarely am I moving the capstan line "back".  

But there are times when a consistent position under the wippen cushion will produce a non-uniform key ratio (let's leave the sharps out of this for now) because of the key ratio variance. That would be driven by the balance rail line that is not parallel to the capstan line. Sometimes you can't win. You can, in such cases, try to determine where exactly the spacing under the wippen should be to compensate but this is often not worth the effort.  So I try not to be too rigid as old Steinways can suffer from lack of uniformity in this respect. 

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320

Original Message:
Sent: 09-30-2023 15:31
From: Joseph Burros
Subject: 4mm difference in determining new Capstan Line between Treble section & Bass and Tenor Section. Any comments??

Hello Everyone,

I am in the process of moving the capstan line further back to the rear of the action on the 1922 Steinway-O I am working on. I have been meticulous in determining where the new capstan line should be located to achieve a 46mm blow, with a 10.1 dip and 1.25" aftertouch. In the bass and tenor sections the location of the new capstan line is the same. But, in the treble section, to achieve my desired specs the new capstan line is about 4mm closer to the front of the key than the new bass and tenor capstan line. It's only a very small distance towards the back of the key from the original treble capstan line. I have tested this new treble capstan position on keys 61 and 83 and the position is the same. 

So, the new treble capstan line is a whopping 4mm toward the front of the key from the new bass and tenor capstan line. Is this ok? Is this acceptable? I am used to seeing a straight capstan line across all 88 keys, but I don't have enough experience to know if some pianos have a capstan line that changes from section to section. It is my understanding that blow distance, dip, and aftertouch should remain consistent for the action to feel even to the player. Can an uneven capstan line between sections be felt by a pianist or is it irrelevant to the optimal performance of the action? 

Thanks for your input on this issue.

Joe

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Joe Burros
Cell: 646-410-7174
jbcello@gmail.com
www.fmi-newengland.com
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