Pianotech

See attached.  This is nothing too new but a slightly more efficient way that I found to approach this.

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

Original Message------

See attached.  This is nothing too new but a slightly more efficient way that I found to approach this.

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

David,

Rather than remove every assembly, why not wait until you have hung the hammers and trimmed the shanks, then set the action on end (so the flanges are vertical), and drop each hammer in turn onto the scale (moving the scale as needed)? The action would need to be propped at the right height to make the hammers hit the scale surface vertically. It seems to me that this gives you an accurate enough picture. Or am I missing something?

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

Original Message:
Sent: 11-24-2015 19:38
From: David Love
Subject: Strike weight smoothing procedure

See attached.  This is nothing too new but a slightly more efficient way that I found to approach this.

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

Measuring SW would be affected by center friction.

------------------------------
Regards,

Jon Page

Original Message:
Sent: 11-25-2015 12:43
From: Fred Sturm
Subject: Strike weight smoothing procedure

David,

Rather than remove every assembly, why not wait until you have hung the hammers and trimmed the shanks, then set the action on end (so the flanges are vertical), and drop each hammer in turn onto the scale (moving the scale as needed)? The action would need to be propped at the right height to make the hammers hit the scale surface vertically. It seems to me that this gives you an accurate enough picture. Or am I missing something?

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

My approach to this, which I will some day write up in detail, is to bore, taper and tail the hammers, and weigh them, dead weight, off the shanks. Then I weigh the shanks using Stanwood's protocol. Then, working in a spread sheet. I organize the hammers and shanks to produce as smooth a curve as possible without changing the "raw" weights. Then I define an ideal curve that follows the "raw" weights as closely as possible without requiring significant weight reductions. Then add a column that gives the needed corrections. I drill and weight the hammer heads on the bench, and only then do I hang them on the shanks. This is a very efficient way to produce a strike weight continuity.

One detail: I prepare all bass hammers in the set, and all extra treble hammers with 90 degree bore, so there may be 92 or 93 hammers to choose from, and 90 hammer shanks...more if it's a shank I commonly use.

------------------------------
Ed Sutton
ed440@me.com
704-536-7926

Original Message:
Sent: 11-25-2015 13:38
From: Jon Page
Subject: Strike weight smoothing procedure

Measuring SW would be affected by center friction.

------------------------------
Regards,

Jon Page

I've never been able to get repeatable hammer weight measurements with the flange screwed to the rail.

------------------------------
Edward McMorrow
Edmonds WA
425-299-3431

Original Message:
Sent: 11-25-2015 14:34
From: Ed Sutton
Subject: Strike weight smoothing procedure

My approach to this, which I will some day write up in detail, is to bore, taper and tail the hammers, and weigh them, dead weight, off the shanks. Then I weigh the shanks using Stanwood's protocol. Then, working in a spread sheet. I organize the hammers and shanks to produce as smooth a curve as possible without changing the "raw" weights. Then I define an ideal curve that follows the "raw" weights as closely as possible without requiring significant weight reductions. Then add a column that gives the needed corrections. I drill and weight the hammer heads on the bench, and only then do I hang them on the shanks. This is a very efficient way to produce a strike weight continuity.

One detail: I prepare all bass hammers in the set, and all extra treble hammers with 90 degree bore, so there may be 92 or 93 hammers to choose from, and 90 hammer shanks...more if it's a shank I commonly use.

------------------------------
Ed Sutton
ed440@me.com
704-536-7926

Original Message:
Sent: 11-25-2015 13:38
From: Jon Page
Subject: Strike weight smoothing procedure

Measuring SW would be affected by center friction.

------------------------------
Regards,

Jon Page

With respect to the flange friction, it can be significant if there are real friction problems, like on a verdigris action - IOW you would want to take that into consideration if you wanted to use this method to evaluate an existing piano, and would probably just want to remove the parts you wanted to evaluate. I happen to have a mild verdigris action in the shop, so I checked one of the high treble hammers with 10 gm + friction, measured again with the friction down to 2 gm, and found that 4.2 gm SW became 5.2. On a heavier hammer the difference was far less, under .5 gm. However I am assuming the friction is within reasonable parameters, and I find that if you are within 1 - 4 gm the effect is within .2 to .3 grams SW measurement. Furthermore, it is as in real life: the real strike weight in action will be affected by flange friction. In any case, the factor should be fairly even throughout (I assume if you are going to this kind of trouble, you have checked/corrected your flange friction), and so if what you are doing (as David Love described) is evening out the curve, it shouldn't affect your ability to do so.

With respect to repeatability of measurement, it depends on what your acceptable parameters are. It will not always repeat at precisely the same reading to the 0.1 gram. It is wise to take, say, four readings and see if you get variation more than .1 gm (I don't, assuming friction is within normal parameters). So, yes, if you want a more absolute precision, you will need to remove all the parts, and go to all the extra trouble and expense of using the fancy ball-bearing devises and whatnot.

I don't have the time for such precision myself, and frankly I don't think it is worth the time. Within + or - 0.2 gm is plenty accurate for me, just as within + or - 1 gm DW/UW/BW is sufficient to aim for, if not quite achieve in every case. There are other aspects of prep where expenditure of time makes far more of a difference, IMO.

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

Original Message:
Sent: 11-26-2015 00:02
From: Edward McMorrow
Subject: Strike weight smoothing procedure

I've never been able to get repeatable hammer weight measurements with the flange screwed to the rail.

------------------------------
Edward McMorrow
Edmonds WA
425-299-3431

Keeping in mind Fred's last comment:

I don't have the time for such precision myself, and frankly I don't think it is worth the time. Within + or - 0.2 gm is plenty accurate for me, just as within + or - 1 gm DW/UW/BW is sufficient to aim for, if not quite achieve in every case. There are other aspects of prep where expenditure of time makes far more of a difference, IMO.

I've found that my original MARS digital scale has begun to demonstrate some erratic behaviors - changing slightly as item sits - so for any discussion-worthy data I'd need to have it upgraded or replaced.  Still, I just tried something:

Series of comparative measurements using a hammer/shank assembly with pinning friction of 4 gr, and strike weight of approx. 8 gr. (8.3g using roller bearing). With all measurements, shank was leveled.  Found that altering location of contact on scale platen could have a .1 - .2 gram effect. Also, all measurements taken 2 ways: 1) placing hammer onto platen - measure; 2) with hammer resting on platen, momentarily slightly depressing platen with finger, release.  Re-measure.  

Next, put assembly in similar position (flange upward) on top of roller bearing sliding block, releveled shank, remeasured.  No notable chance

Next, clamped flange to top of roller-bearing sliding block to measure from center pin with friction as a component of measurement. Releveled. 

Found .5 gram difference between measurement 1 & 2.  Presumably, higher friction would produce a greater differential, but, as with friction in measuring UW & DW, dividing by 2 would seem to bring result in line with the original roller-bearing spec.

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565

Original Message:
Sent: 11-27-2015 11:28
From: Fred Sturm
Subject: Strike weight smoothing procedure

With respect to the flange friction, it can be significant if there are real friction problems, like on a verdigris action - IOW you would want to take that into consideration if you wanted to use this method to evaluate an existing piano, and would probably just want to remove the parts you wanted to evaluate. I happen to have a mild verdigris action in the shop, so I checked one of the high treble hammers with 10 gm + friction, measured again with the friction down to 2 gm, and found that 4.2 gm SW became 5.2. On a heavier hammer the difference was far less, under .5 gm. However I am assuming the friction is within reasonable parameters, and I find that if you are within 1 - 4 gm the effect is within .2 to .3 grams SW measurement. Furthermore, it is as in real life: the real strike weight in action will be affected by flange friction. In any case, the factor should be fairly even throughout (I assume if you are going to this kind of trouble, you have checked/corrected your flange friction), and so if what you are doing (as David Love described) is evening out the curve, it shouldn't affect your ability to do so.

With respect to repeatability of measurement, it depends on what your acceptable parameters are. It will not always repeat at precisely the same reading to the 0.1 gram. It is wise to take, say, four readings and see if you get variation more than .1 gm (I don't, assuming friction is within normal parameters). So, yes, if you want a more absolute precision, you will need to remove all the parts, and go to all the extra trouble and expense of using the fancy ball-bearing devises and whatnot.

I don't have the time for such precision myself, and frankly I don't think it is worth the time. Within + or - 0.2 gm is plenty accurate for me, just as within + or - 1 gm DW/UW/BW is sufficient to aim for, if not quite achieve in every case. There are other aspects of prep where expenditure of time makes far more of a difference, IMO.

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

David Skolnik,

In response to your comments on measuring, I agree with you: you will get different measurements depending how you take them. If you want something as completely accurate as possible, as a raw weight, then the Stanwood protocol with the roller bearing is probably the way to go.

I take all measurements (in the scenario of shanks/hammers attached to the stack) the same way: I drop the hammer onto the middle of the platen, from about 45 degrees. (That yields a higher number than lightly laying the hammer on the scale, hence closer to the roller bearing method). I do that four times. If my measurements vary by no more than 0.1 gm, I am quite happy - and I am almost always happy <G>. If they vary by more, I strongly suspect a frictional problem, and that hammer will be removed from the rail to check it.

The fact that my measurement may be up to 0.5 gm lighter than one obtained on the roller bearing does not worry me. The measurements will all be consistently lower, and it is the consistency that matters - that is what I am checking for, consistency from hammer to hammer. When I am taking the measurements in this way (as a final check in a rebuilding job, and as I suggested to David Love for his similar check and correction - obviously my standards are not up to his, but that also doesn't worry me), I am only concerned with finding discrepancies. If they are large enough, I correct them. 

In rebuilding, I put each hammer on the scale, and correct any large discrepancies before hanging. After hanging and trimming shanks, I do not remove them from the stack, I simply check them (obviously with the shank included this time) once again as described. I find this is enough to meet the standards in my world, where money (and therefore time) is tight. This is true for my private work as well as my university work. I live in one of the poorest states in the country, so I need to adapt to that reality. 

Over the years, I have found that meticulous prep (as in travel, square, mate, voice, regulate, and the like) is a better investment of my time than the touch weight procedures I hear others describe: I've tried those, and have not found that the extra time and effort made a discernible difference. Hence, I have pulled back and do a modified version. My work at this point is based more on Darrel Fandrich's philosophy than on David Stanwood's (there are areas where they are somewhat parallel).

I have no desire to set myself up as the best rebuilder or technician in the world, nor am I trying to persuade everybody else that my way is the best. I am simply reporting what I do, with the thought that it might be helpful to someone.

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

Original Message:
Sent: 11-27-2015 13:11
From: David Skolnik
Subject: Strike weight smoothing procedure

Keeping in mind Fred's last comment:

I don't have the time for such precision myself, and frankly I don't think it is worth the time. Within + or - 0.2 gm is plenty accurate for me, just as within + or - 1 gm DW/UW/BW is sufficient to aim for, if not quite achieve in every case. There are other aspects of prep where expenditure of time makes far more of a difference, IMO.

I've found that my original MARS digital scale has begun to demonstrate some erratic behaviors - changing slightly as item sits - so for any discussion-worthy data I'd need to have it upgraded or replaced.  Still, I just tried something:

Series of comparative measurements using a hammer/shank assembly with pinning friction of 4 gr, and strike weight of approx. 8 gr. (8.3g using roller bearing). With all measurements, shank was leveled.  Found that altering location of contact on scale platen could have a .1 - .2 gram effect. Also, all measurements taken 2 ways: 1) placing hammer onto platen - measure; 2) with hammer resting on platen, momentarily slightly depressing platen with finger, release.  Re-measure.  

Next, put assembly in similar position (flange upward) on top of roller bearing sliding block, releveled shank, remeasured.  No notable chance

Next, clamped flange to top of roller-bearing sliding block to measure from center pin with friction as a component of measurement. Releveled. 

Found .5 gram difference between measurement 1 & 2.  Presumably, higher friction would produce a greater differential, but, as with friction in measuring UW & DW, dividing by 2 would seem to bring result in line with the original roller-bearing spec.

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565

Of course it's significant.  And you don't know if you have a problem unless you measure the friction.  When I have the flanges off taking the strike weight measurements I take that opportunity to check the flange friction.  It makes a difference for the same reason that we use balance weight as the standard rather than just down weight.  I realize many people don't want to take that time but let's not mistake not wanting to take the time for what makes a difference.  We all have our priorities and excuses I suppose.  Quality custom work has a higher bar than most universities are willing to pay for it seems. 

Taking the strike weights can be very important as you can see..  On this particular piano I had some significant leaps in the measured SW  that required modification (see below).  

With the method I suggest it doesn't take that long. It's both faster and more accurate depending on how many details you are willing to leave out--we all have different standards, I suppose.  

Prepare hammers and hang them.  Remove hammers from rail, trim shanks, take strikeweights and test flange friction (I use the swing method and address outliers on the spot).  Return the hammers to the rail.  Spread sheet the strike weights and calculate the trendline curve (my existing spreadsheet does this automatically).  Calculate the final SW curve and then with the hammers on the rail as shown in my previous post, make smooth curve modifications.  This took about an hour using my suggested method on this action.  There were a lot of modifications to be made on this one.  Often it's less.  Now that I have the exact strike weights I can simply use my spreadsheet to calculate the front weight specs (since I know the action ratio) and set my weights to achieve the targeted balance weight without ever having to take an upweight or downweight measurement (except to spot test). That measuring of UW DW and figuring out FW change takes a fair amount of time and, as I've pointed out before, taking UW and DW measurements is very prone to measurement error.  Precalculating the FW, btw, can't be done without knowing the strike weights (or the component mass (shank and hammer), as well as the action ratio.  

In the end not only is this way more efficient but more accurate and produces a better more uniform product.  I've seen plenty of actions where people just wing it and leave something with quite a bit of variation.  While the customer may not always know it, I do.  That's enough for me to move ahead.   It's not a matter of aiming for .1 grams (that's simply what the scales are calibrated to).  In fact, I don't bother to make changes for .1 grams.  Has to reach double that for me to make a change.  There is always a potential for small degree of measurement error.

Like I said, if people want to dumb down their own final product that's fine.  But don't diminish a general approach which produces a superior outcome because you don't want to be bothered.  That's simply your choice.  I thought you had a higher standard based on your other postings on other subjects.

Here's the entire chart. For the final strike weight I added .2 grams to minimize SW reduction which does require a removal of the assembly from the rail.  Note that down at note 65 a change of 1 full gram was required and there are plenty of areas where significant changes were made (over .5 grams).  This type of variation is pretty typical and I do very uniform table saw tapering.  I must say, the action performs beautifully ;-).

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

Original Message:
Sent: 11-27-2015 11:28
From: Fred Sturm
Subject: Strike weight smoothing procedure

With respect to the flange friction, it can be significant if there are real friction problems, like on a verdigris action - IOW you would want to take that into consideration if you wanted to use this method to evaluate an existing piano, and would probably just want to remove the parts you wanted to evaluate. I happen to have a mild verdigris action in the shop, so I checked one of the high treble hammers with 10 gm + friction, measured again with the friction down to 2 gm, and found that 4.2 gm SW became 5.2. On a heavier hammer the difference was far less, under .5 gm. However I am assuming the friction is within reasonable parameters, and I find that if you are within 1 - 4 gm the effect is within .2 to .3 grams SW measurement. Furthermore, it is as in real life: the real strike weight in action will be affected by flange friction. In any case, the factor should be fairly even throughout (I assume if you are going to this kind of trouble, you have checked/corrected your flange friction), and so if what you are doing (as David Love described) is evening out the curve, it shouldn't affect your ability to do so.

With respect to repeatability of measurement, it depends on what your acceptable parameters are. It will not always repeat at precisely the same reading to the 0.1 gram. It is wise to take, say, four readings and see if you get variation more than .1 gm (I don't, assuming friction is within normal parameters). So, yes, if you want a more absolute precision, you will need to remove all the parts, and go to all the extra trouble and expense of using the fancy ball-bearing devises and whatnot.

I don't have the time for such precision myself, and frankly I don't think it is worth the time. Within + or - 0.2 gm is plenty accurate for me, just as within + or - 1 gm DW/UW/BW is sufficient to aim for, if not quite achieve in every case. There are other aspects of prep where expenditure of time makes far more of a difference, IMO.

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

As I mentioned years ago, to avoid drastic differences from note to note, match the hammer weight to the shank Strike Weight. Your final alteration will be minimized. First you have to weigh the entire set and plot them on a chart. Remove those that are too high and too low and the one that has the under felt half-way across. Weigh the SW of the shanks and separate them into piles; I've measured them between 2.2 g and 1.4 g.  A heavy shank on a heavy hammer assembled next to a light shank and light hammer will result in a large weight differentiaI. I don't want the hap-hazzard approach to SW. I also go a step further and measure the knuckle height and divine each grouping into low-med-high; then group like sized knuckle heights according to the weight parameters. it's a minor aspect, but the LO buttons have a more even level to them and I believe a more even touch. The more refined each section/area is, the finer the touch perception. I'll try to group the tallest knuckles in the treble or at the low end, leaving the center for more even parameters. If the mid-high tenor has an elevated string plane, I'll place the taller knuckles there. The devil is in the details. is it worth it? I think it is but in any case, it gives me that warm fuzzy feeling of a job well done if not over done :-)    More is better, right? How fine do we want to split hairs?

------------------------------
Regards,

Jon Page

Original Message:
Sent: 11-27-2015 15:01
From: David Love
Subject: Strike weight smoothing procedure

Of course it's significant.  And you don't know if you have a problem unless you measure the friction.  When I have the flanges off taking the strike weight measurements I take that opportunity to check the flange friction.  It makes a difference for the same reason that we use balance weight as the standard rather than just down weight.  I realize many people don't want to take that time but let's not mistake not wanting to take the time for what makes a difference.  We all have our priorities and excuses I suppose.  Quality custom work has a higher bar than most universities are willing to pay for it seems. 

Taking the strike weights can be very important as you can see..  On this particular piano I had some significant leaps in the measured SW  that required modification (see below).  

With the method I suggest it doesn't take that long. It's both faster and more accurate depending on how many details you are willing to leave out--we all have different standards, I suppose.  

Prepare hammers and hang them.  Remove hammers from rail, trim shanks, take strikeweights and test flange friction (I use the swing method and address outliers on the spot).  Return the hammers to the rail.  Spread sheet the strike weights and calculate the trendline curve (my existing spreadsheet does this automatically).  Calculate the final SW curve and then with the hammers on the rail as shown in my previous post, make smooth curve modifications.  This took about an hour using my suggested method on this action.  There were a lot of modifications to be made on this one.  Often it's less.  Now that I have the exact strike weights I can simply use my spreadsheet to calculate the front weight specs (since I know the action ratio) and set my weights to achieve the targeted balance weight without ever having to take an upweight or downweight measurement (except to spot test). That measuring of UW DW and figuring out FW change takes a fair amount of time and, as I've pointed out before, taking UW and DW measurements is very prone to measurement error.  Precalculating the FW, btw, can't be done without knowing the strike weights (or the component mass (shank and hammer), as well as the action ratio.  

In the end not only is this way more efficient but more accurate and produces a better more uniform product.  I've seen plenty of actions where people just wing it and leave something with quite a bit of variation.  While the customer may not always know it, I do.  That's enough for me to move ahead.   It's not a matter of aiming for .1 grams (that's simply what the scales are calibrated to).  In fact, I don't bother to make changes for .1 grams.  Has to reach double that for me to make a change.  There is always a potential for small degree of measurement error.

Like I said, if people want to dumb down their own final product that's fine.  But don't diminish a general approach which produces a superior outcome because you don't want to be bothered.  That's simply your choice.  I thought you had a higher standard based on your other postings on other subjects.

Here's the entire chart. For the final strike weight I added .2 grams to minimize SW reduction which does require a removal of the assembly from the rail.  Note that down at note 65 a change of 1 full gram was required and there are plenty of areas where significant changes were made (over .5 grams).  This type of variation is pretty typical and I do very uniform table saw tapering.  I must say, the action performs beautifully ;-).

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

Well that does take s bit longer that way as you have to measure each component. But I agree the devil is in the details and precision balancing pays dividends.

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

Original Message:
Sent: 11-27-2015 15:37
From: Jon Page
Subject: Strike weight smoothing procedure

As I mentioned years ago, to avoid drastic differences from note to note, match the hammer weight to the shank Strike Weight. Your final alteration will be minimized. First you have to weigh the entire set and plot them on a chart. Remove those that are too high and too low and the one that has the under felt half-way across. Weigh the SW of the shanks and separate them into piles; I've measured them between 2.2 g and 1.4 g.  A heavy shank on a heavy hammer assembled next to a light shank and light hammer will result in a large weight differentiaI. I don't want the hap-hazzard approach to SW. I also go a step further and measure the knuckle height and divine each grouping into low-med-high; then group like sized knuckle heights according to the weight parameters. it's a minor aspect, but the LO buttons have a more even level to them and I believe a more even touch. The more refined each section/area is, the finer the touch perception. I'll try to group the tallest knuckles in the treble or at the low end, leaving the center for more even parameters. If the mid-high tenor has an elevated string plane, I'll place the taller knuckles there. The devil is in the details. is it worth it? I think it is but in any case, it gives me that warm fuzzy feeling of a job well done if not over done :-)    More is better, right? How fine do we want to split hairs?

------------------------------
Regards,

Jon Page

Yes, friction in the flange influences the sw measurement.

I have not found a way to measure sw without the assembly off the rail but I only like to have to remove them once. Ed Sutton's  procedure seems like a lot of extra work of weighing components and dry assembly for purposes if determing weight. The procedure I outlined allows for direct assembly, single removal for weighing and then modification of the weight for smoothing without a second removal. The procedure of determining the sw curve using a trend line calculation uses the existing natural curve of the set which I generally find adequate. A predetermination of the approximate weight required and the weighing of a few samples can help you determine the amount of tapering of the hammer in preparation.

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

Original Message:
Sent: 11-25-2015 12:43
From: Fred Sturm
Subject: Strike weight smoothing procedure

David,

Rather than remove every assembly, why not wait until you have hung the hammers and trimmed the shanks, then set the action on end (so the flanges are vertical), and drop each hammer in turn onto the scale (moving the scale as needed)? The action would need to be propped at the right height to make the hammers hit the scale surface vertically. It seems to me that this gives you an accurate enough picture. Or am I missing something?

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

David Stanwood developed a system to measure SW w/ h/s/f/ attached to the rail. It involved a swivel mounting system for the top action frame so as to measure SW with hammer rising and hammer lowering. It was a while ago but I think the difference was the friction and average was the SW. I know for sure that it measured in both directions, the processing of that data might be different from what I recall now. I haven't heard much of the procedure since my first encounter. 

------------------------------
Regards,

Jon Page

edited 11/28, 8:15 AM

This is an editing trial. When attempted before it posted a new e-mail and not just revise the original. Let's see what happens...

>the processing of that data might be different from what I presume now. 

the processing of that data might be different from what I recall now.

<<edited in previous post>> ((second edit on this entry))

I wish there were a way to edit text. I suppose the problem is with the instant dispersal to e-mail accounts. If it were web only, it could happen. i don't see the need for the 'instant messaging' aspect of broadcasting to recipients' e-mail accounts. 

 

David-

My procedure requires no dry fitting, My understanding is that the weight of the naked shank, measured as a lever using Stanwood's protocol, plus the dead weight of the unattached hammer head, will equal the strike weight when the hammer is hung on the shank.

I prepare and weigh all hammer heads, entering the weights on a spread sheet.

Then I weigh all shanks, writing the "shank strike weight" on each flange. I sort all shanks, mounting them on little racks that grab the knuckles. This allows me to gang test the flanges by tapping the racks and observing the flange movements, or to test each flange with a gram gauge, and repin as needed.

Then, on the spread sheet I enter the mean weight value of the shanks. If, say, the spread was 1.4 to 2.0 with most shanks 1.6 to 1.8, I will enter a shank weight value of 1.7 on my spread sheet and calculate the strike weights of all hammer assemblies with 1.7 gram shanks. From this I establish a curve that fits the given rough data. Then I begin substituting the 1.4, 1.5, 1.6, 1.8, 1.9 and 2.0 shanks to make corrections without adding or removing weight from the hammers. My goal is to achieve the target curve without having to remove hammer weight, and to not add more than 0.6 grams to any hammer heads, which I can do with one piece of lead. If I have more than 88 hammers and shanks, all the better. All shuffling is done on the spreadsheet, not via dry fitting.

My hammer heads are in a tray, organized by sections, that allows me to mark and drill for weight where needed, add the lead, and return the hammer, ready to hang. Also, I have a tray with precut leads, .1 to .6 grams. I don't often use the .1 gram leads, as I allow a .1 gram fudge, as long as it does not make a bump in the curve.

------------------------------
Ed Sutton
ed440@me.com
704-536-7926

Original Message:
Sent: 11-27-2015 10:17
From: David Love
Subject: Strike weight smoothing procedure

Yes, friction in the flange influences the sw measurement.

I have not found a way to measure sw without the assembly off the rail but I only like to have to remove them once. Ed Sutton's  procedure seems like a lot of extra work of weighing components and dry assembly for purposes if determing weight. The procedure I outlined allows for direct assembly, single removal for weighing and then modification of the weight for smoothing without a second removal. The procedure of determining the sw curve using a trend line calculation uses the existing natural curve of the set which I generally find adequate. A predetermination of the approximate weight required and the weighing of a few samples can help you determine the amount of tapering of the hammer in preparation.

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

Original Message:
Sent: 11-25-2015 12:43
From: Fred Sturm
Subject: Strike weight smoothing procedure

David,

Rather than remove every assembly, why not wait until you have hung the hammers and trimmed the shanks, then set the action on end (so the flanges are vertical), and drop each hammer in turn onto the scale (moving the scale as needed)? The action would need to be propped at the right height to make the hammers hit the scale surface vertically. It seems to me that this gives you an accurate enough picture. Or am I missing something?

------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
http://www.artoftuning.com
"We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda

Ed S.

Clearly your system is thorough and works and we agree on the end goal.  My posting this was to show how to get to a smooth sw with the least number of steps.  Your system requires the weighing of both the hammer and the shank, marking the shanks (as well as entering them in the spreadsheet) and then sorting them and Jon's is similar. In my system I can simply install shanks out of the box, prep hammers and hang (once I determine general sw target and taper accordingly). I then have the step of removing shanks one time to trim and weigh recording the sw on the spreadsheet. The addition of solder to the hammers generally goes pretty fast with the shanks remaining on the rail. 

There are obviously different ways to go about this. In general I think we should always be looking at our efficiency with the idea of getting to our goal with the least amount of duplication of work without sacrificing our end result. .

Fred B.

Note that the trendline formula will vary slightly with each set.  The FW formula can be derived from Stanwood's equation of balance or a more conventional engineering formula as is present in Gravagne's program which he offers for sale. The FW curve will always be a reflection of the SW curve all other things remaining constant.

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

Original Message:
Sent: 11-27-2015 19:57
From: Ed Sutton
Subject: Strike weight smoothing procedure

David-

My procedure requires no dry fitting, My understanding is that the weight of the naked shank, measured as a lever using Stanwood's protocol, plus the dead weight of the unattached hammer head, will equal the strike weight when the hammer is hung on the shank.

I prepare and weigh all hammer heads, entering the weights on a spread sheet.

Then I weigh all shanks, writing the "shank strike weight" on each flange. I sort all shanks, mounting them on little racks that grab the knuckles. This allows me to gang test the flanges by tapping the racks and observing the flange movements, or to test each flange with a gram gauge, and repin as needed.

Then, on the spread sheet I enter the mean weight value of the shanks. If, say, the spread was 1.4 to 2.0 with most shanks 1.6 to 1.8, I will enter a shank weight value of 1.7 on my spread sheet and calculate the strike weights of all hammer assemblies with 1.7 gram shanks. From this I establish a curve that fits the given rough data. Then I begin substituting the 1.4, 1.5, 1.6, 1.8, 1.9 and 2.0 shanks to make corrections without adding or removing weight from the hammers. My goal is to achieve the target curve without having to remove hammer weight, and to not add more than 0.6 grams to any hammer heads, which I can do with one piece of lead. If I have more than 88 hammers and shanks, all the better. All shuffling is done on the spreadsheet, not via dry fitting.

My hammer heads are in a tray, organized by sections, that allows me to mark and drill for weight where needed, add the lead, and return the hammer, ready to hang. Also, I have a tray with precut leads, .1 to .6 grams. I don't often use the .1 gram leads, as I allow a .1 gram fudge, as long as it does not make a bump in the curve.

------------------------------
Ed Sutton
ed440@me.com
704-536-7926

I suppose we need stopwatches...

My approach to hammer replacement has become highly organized over the years.

Most recently I've purchased Chris Brown's Regulation Station, and this adds to the ease of working.

Having tested flanges in advance, 45 at a time on my flange racks, which are just 2x4s with slots cut to hold the shanks by the knuckles (slots are lined with foam weatherstrip material)...the flanges hang free for quick test...and shank order calculated on the spread sheet...the shanks go on the stack and are aligned and traveled on the station...then pre-weighted hammers are hung on the station, shanks are trimmed, travel and alignment are checked and regulation begins.

------------------------------
Ed Sutton
ed440@me.com
704-536-7926

Original Message:
Sent: 11-28-2015 00:43
From: David Love
Subject: Strike weight smoothing procedure

Ed S.

Clearly your system is thorough and works and we agree on the end goal.  My posting this was to show how to get to a smooth sw with the least number of steps.  Your system requires the weighing of both the hammer and the shank, marking the shanks (as well as entering them in the spreadsheet) and then sorting them and Jon's is similar. In my system I can simply install shanks out of the box, prep hammers and hang (once I determine general sw target and taper accordingly). I then have the step of removing shanks one time to trim and weigh recording the sw on the spreadsheet. The addition of solder to the hammers generally goes pretty fast with the shanks remaining on the rail. 

There are obviously different ways to go about this. In general I think we should always be looking at our efficiency with the idea of getting to our goal with the least amount of duplication of work without sacrificing our end result. .

Fred B.

Note that the trendline formula will vary slightly with each set.  The FW formula can be derived from Stanwood's equation of balance or a more conventional engineering formula as is present in Gravagne's program which he offers for sale. The FW curve will always be a reflection of the SW curve all other things remaining constant.

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

I'm not trying to be argumentative. Let's just say that I think it pays to examine one's procedures periodically to see if they are the most efficient without compromising quality. Since we tend to do these things ourselves we don't tend to think about it. If we were employing someone and paying them by the hour we probably would.

I've found that ways of doing things tend to evolve out of habit. When I reexamine things I often find that there's a faster or more efficient way. Personally, I don't mind saving the time as life has other things to offer.

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

Original Message:
Sent: 11-29-2015 05:54
From: Ed Sutton
Subject: Strike weight smoothing procedure

I suppose we need stopwatches...

My approach to hammer replacement has become highly organized over the years.

Most recently I've purchased Chris Brown's Regulation Station, and this adds to the ease of working.

Having tested flanges in advance, 45 at a time on my flange racks, which are just 2x4s with slots cut to hold the shanks by the knuckles (slots are lined with foam weatherstrip material)...the flanges hang free for quick test...and shank order calculated on the spread sheet...the shanks go on the stack and are aligned and traveled on the station...then pre-weighted hammers are hung on the station, shanks are trimmed, travel and alignment are checked and regulation begins.

------------------------------
Ed Sutton
ed440@me.com
704-536-7926

Hi David,

Thank you for sharing your smoothing procedure. I plan to use your drilling and swaging on rail this next week. The equation for creating a targeted SW spreadsheet was also helpful. Do you have a similiar equation for creating and smoothing FW?

Thanks

Fred Brown RPT

------------------------------
Fred Brown
Saint Augustine FL
904-687-8353

Original Message:
Sent: 11-24-2015 19:38
From: David Love
Subject: Strike weight smoothing procedure

See attached.  This is nothing too new but a slightly more efficient way that I found to approach this.

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