Pianotech

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Nick.

I see. It's kind of like following what you should and shouldn't eat.  Things keep changing. That's a bit different than the last time I looked at you program. I don't think you were using end of the stroke at that time. Hopefully this helps to answer Jim's question as to why folks are arriving at different numbers. 

thanks for taking the time. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Nick.

I see. It's kind of like following what you should and shouldn't eat.  Things keep changing. That's a bit different than the last time I looked at you program. I don't think you were using end of the stroke at that time. Hopefully this helps to answer Jim's question as to why folks are arriving at different numbers. 

thanks for taking the time. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

@Let me add, and just thinking out loud here. So measuring the key dip/hammer travel relationship would presumably be an AR "average" since we're measuring from the beginning of the strike to the end (or quasi end) and since the AR changes through the stroke this represents some type of average. 

As far as MAR it seems to me (if that were actually being used as a guide for how to set up AR/SW relationships) that it would be more important to measure at the beginning of the strike since the force to overcome inertia is highest at the onset of key movement, not at the end. 

To add to the confusion, an AR of 5.5 has long been talked about as a standard by many manufacturers. Clearly they were using some different form of measurement. 

From our previous discussions (now some years old) measurements were being taken with the key at rest so I gather your methods have changed since then. 

Nick.

I see. It's kind of like following what you should and shouldn't eat.  Things keep changing. That's a bit different than the last time I looked at you program. I don't think you were using end of the stroke at that time. Hopefully this helps to answer Jim's question as to why folks are arriving at different numbers. 

thanks for taking the time. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

@Let me add, and just thinking out loud here. So measuring the key dip/hammer travel relationship would presumably be an AR "average" since we're measuring from the beginning of the strike to the end (or quasi end) and since the AR changes through the stroke this represents some type of average. 

As far as MAR it seems to me (if that were actually being used as a guide for how to set up AR/SW relationships) that it would be more important to measure at the beginning of the strike since the force to overcome inertia is highest at the onset of key movement, not at the end. 

To add to the confusion, an AR of 5.5 has long been talked about as a standard by many manufacturers. Clearly they were using some different form of measurement. 

From our previous discussions (now some years old) measurements were being taken with the key at rest so I gather your methods have changed since then. 

Nick.

I see. It's kind of like following what you should and shouldn't eat.  Things keep changing. That's a bit different than the last time I looked at you program. I don't think you were using end of the stroke at that time. Hopefully this helps to answer Jim's question as to why folks are arriving at different numbers. 

thanks for taking the time. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

@Let me add, and just thinking out loud here. So measuring the key dip/hammer travel relationship would presumably be an AR "average" since we're measuring from the beginning of the strike to the end (or quasi end) and since the AR changes through the stroke this represents some type of average. 

As far as MAR it seems to me (if that were actually being used as a guide for how to set up AR/SW relationships) that it would be more important to measure at the beginning of the strike since the force to overcome inertia is highest at the onset of key movement, not at the end. 

To add to the confusion, an AR of 5.5 has long been talked about as a standard by many manufacturers. Clearly they were using some different form of measurement. 

From our previous discussions (now some years old) measurements were being taken with the key at rest so I gather your methods have changed since then. 

Nick.

I see. It's kind of like following what you should and shouldn't eat.  Things keep changing. That's a bit different than the last time I looked at you program. I don't think you were using end of the stroke at that time. Hopefully this helps to answer Jim's question as to why folks are arriving at different numbers. 

thanks for taking the time. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?   

 

Gravagne wrote: "The AR cannot be changed simply by changing the blow, or any of these variables. For example, shortening the blow will increase the aftertouch and vice versa."

I don't think anyone was arguing that you can change the AR by shortening the blow but you can (and often must) compensate for an AR which delivers non standard regulation specs by changing those specs. In other words with a very low AR you may be required to increase the dip, shorten the blow or reduce the after touch or some combination of those three. There's no free lunch. You have to pay the piper somewhere. 

′Dean

There are clearly different ways of measuring the in/out of each lever and I think that may account for differences. Last I checked, a 4.9-5.0 AR would be outside of the "green zone" for Gravagne's program. I use his system for measuring each lever and that would be low for me too. I can't speak to what Baldassin/Renner advocate now but know Nick has been involved there.  

Interestingly, your numbers comport with what Rick Wheeler advocated but I believe they (Wheeler and Gravagne) used different methods. In the Stanwood system it seems that 4.9 - 5.0 would also be outside of his normal target, but I'll have to let him confirm that. Wheelers 4.9 yielded something quite different using mine or Gravagne's methodology  

Product of levers is only as good as our agreement on how each lever is measured so we should verify that  before going further. 

I want to discuss measuring action ratios, following a confusing response on the recent "half-punching" thread. Distance measuring action ratios can be confusing, and we need to know we are talking about the same thing when trying to communicate about this stuff. Here's is David Love's comment regarding action ratio measurement, that makes me think we are not communicating precisely...David's comment below, says quite clearly that a 5.25 action ratio, at .390" dip,  will result in a very shy blow.

David L< I agree that if you push the leverage down to 5.25 that you will want a higher static balance weight.  However, I don't see you  can possibly accomplish a 3.90" dip with a 5.25 leverage (if that's actually what it is--taking accurate measurements with dip/travel is tricky).  I've seen plenty of 5.3 targeted leverages and the dip is nowhere near that low, not without a very short blow distance.  Too short for anything I would want.

Contrary to David's comment, my own empirical evidence says something quite different. I see a 5.23 directly measured action ratio, providing a carefully measured set of pretty common manufacturer's regulation spec's: .390"dip/ .040" aftertouch/ 1.75" blow/ 2mm letoff.  1.75" blow is what I measure, produced by my measured 5.23 AR. 

So,  I don't think we are communicating precisely. As this action ratio confusion seems to come up often, at least to my mind, the confusion around measuring it can muck up the communication often, I think.  So I want to suss out what the communication mismatch may be.

After reading David's comment, which I knew did not jive with my experience, I went out the shop to double check my measurements, to make sure I wasn't talking through my hat. There are two ways I measure action ratio. The two methods double check each other. One is direct measurement of the ratio, and the other is to confirm that the regulation specs I target are actually achieved. I measure both of these with the highest l level of precision the felts and other materials in the system will allow.  As someone  who set up production shop runs where the machinery had to cut 100's of water tight sash joints, in a life previous to life in piano land, I know where to look for measurement inaccuracy, and how to avoid the major problem of making dimensional assumptions. Here is how I take my measurements.

1- To start, before hanging hammers, I draw a line across the set hammer crowns indicating the strike point of each hammer, and refer to that line throughout the rest of the action process. In the installed actions, this line ends up being pretty darn close to the empirical strike point on the crown. In this case, I'm more interested in measuring to the exact same place on the crown for the two different measurements.

 Using a 12" machinists height gauge, with a dial scale, Measuring from one point on the marked strike point on a given sample hammer, I take a measurement with hammer at rest, using the machinist's height gauge, and record the reading. Then with a separate machinists height gauge at the key front, set the gauge to just touch the top of the front of the key at rest. So I have my starting positions clearly indicated. Then, at the height gauge at the front of the key, I insert a shim of known thickness (.246), between the height gauge and the keytop, thus depressing it a precisely known dimension, ie ,246".  Then I go around to the back of the action, and measure to the same point on the crown of the hammer I indicated to in the first hammer-at-rest rest reading, using the 12" machinist height gauge, at the new raised position of the hammer at .246" dip. Record that t measurement and do the math: (raised hammer reading - hammer at rest)/.246 .  (7.695-6.413)/ .246 = 5.23

This is precise measurement, and does not depend on relative positions of other parts. So the action, at this note is according to this technique, 5.23, and is as precise as can be had in this kind of setup. Here are pics of this process...the last pic shows that the jack tender has not touched the letoff button, which is essential in taking this measurement;

2- Now, I check the regulation spec to a similar level of precision, to confirm the ratio achieves my regulation specs. I can post pics of this if requested. Using a dial indicator, measure the actual dip of that note, which comes in within a few thousandths of .390.  Measure from the strike height of my string plane gantry, to the marked crown of the at rest hammer with a rule, 1.75". Confirm letoff to the gantry at  2mm (.078"). Measure aftertouch using a shim that I have proven with a dial indicator, results in 040" aftertouch movement of the key.

So, using this technique, which is as precise as it is possible to be in a setup like this, I get a 5.23 ratio allows .390 dip/1.75 blow/2mm letoff/.040 aftertouch.

That's how I take the measurements, since I work using dimensional leverage analysis exclusively, as opposed to weight analysis. So my question for David is, how do you take this measurement differently, in a way that 5.25 (actually 5.23 in this case) cannot provide adequate blow given .390 dip?  Are we talking about the same thing?  Or perhaps do you consider 1.75 blow a shy blow?