Pianotech

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Hi Scott,

Strike Weight Ratios levels usually are close to distance ratios.    Confirming that your Strike Weight Ratio calculation is Strike Weight Ratio = (BW + FW - (Key Weight Ratio x Wippen Radius Weight))/Strike Wt.  How many values did you calculate and what are the results?    I like to add a weight to the hammer when measuring with the 6mm dip.  I find that gives a more accurate result with the distance ratio. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-08-2023 22:13
From: David Love
Subject: Action ratio measurement discrepancy

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

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

Original Message:
Sent: 10-08-2023 17:15
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

My default setting has been 37g BW with 80-85% of FW maximum at C4 for some time now. Interestingly, more people find that slightly heavy than light. The trend is that professional pianists find it s a bit light, amateurs find it a bit heavy. I've now taken to installing mini binder clip "sliders" midway on the shank and then targeting those same specs. That gives me an ~ 4-5 gram spread on the balance weight achieved by moving the slider either toward the hammer or toward the knuckle with an accompanying change in inertia. A simple, adjustable action. 

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

Original Message:
Sent: 10-11-2023 08:02
From: David Stanwood
Subject: Action ratio measurement discrepancy

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-08-2023 22:13
From: David Love
Subject: Action ratio measurement discrepancy

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

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

Original Message:
Sent: 10-08-2023 17:15
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Someone should invent special pliers for opening bindier clips quickly!

My default setting has been 37g BW with 80-85% of FW maximum at C4 for some time now. Interestingly, more people find that slightly heavy than light. The trend is that professional pianists find it s a bit light, amateurs find it a bit heavy. I've now taken to installing mini binder clip "sliders" midway on the shank and then targeting those same specs. That gives me an ~ 4-5 gram spread on the balance weight achieved by moving the slider either toward the hammer or toward the knuckle with an accompanying change in inertia. A simple, adjustable action. 

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

Original Message:
Sent: 10-11-2023 08:02
From: David Stanwood
Subject: Action ratio measurement discrepancy

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-08-2023 22:13
From: David Love
Subject: Action ratio measurement discrepancy

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

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

Original Message:
Sent: 10-08-2023 17:15
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

My default setting has been 37g BW with 80-85% of FW maximum at C4 for some time now. Interestingly, more people find that slightly heavy than light. The trend is that professional pianists find it s a bit light, amateurs find it a bit heavy. I've now taken to installing mini binder clip "sliders" midway on the shank and then targeting those same specs. That gives me an ~ 4-5 gram spread on the balance weight achieved by moving the slider either toward the hammer or toward the knuckle with an accompanying change in inertia. A simple, adjustable action. 

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

Original Message:
Sent: 10-11-2023 08:02
From: David Stanwood
Subject: Action ratio measurement discrepancy

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-08-2023 22:13
From: David Love
Subject: Action ratio measurement discrepancy

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

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

Original Message:
Sent: 10-08-2023 17:15
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

David, this strikes me as brilliant!

My default setting has been 37g BW with 80-85% of FW maximum at C4 for some time now. Interestingly, more people find that slightly heavy than light. The trend is that professional pianists find it s a bit light, amateurs find it a bit heavy. I've now taken to installing mini binder clip "sliders" midway on the shank and then targeting those same specs. That gives me an ~ 4-5 gram spread on the balance weight achieved by moving the slider either toward the hammer or toward the knuckle with an accompanying change in inertia. A simple, adjustable action. 

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

Original Message:
Sent: 10-11-2023 08:02
From: David Stanwood
Subject: Action ratio measurement discrepancy

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-08-2023 22:13
From: David Love
Subject: Action ratio measurement discrepancy

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

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

Original Message:
Sent: 10-08-2023 17:15
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

David, this strikes me as brilliant!

My default setting has been 37g BW with 80-85% of FW maximum at C4 for some time now. Interestingly, more people find that slightly heavy than light. The trend is that professional pianists find it s a bit light, amateurs find it a bit heavy. I've now taken to installing mini binder clip "sliders" midway on the shank and then targeting those same specs. That gives me an ~ 4-5 gram spread on the balance weight achieved by moving the slider either toward the hammer or toward the knuckle with an accompanying change in inertia. A simple, adjustable action. 

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

Original Message:
Sent: 10-11-2023 08:02
From: David Stanwood
Subject: Action ratio measurement discrepancy

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-08-2023 22:13
From: David Love
Subject: Action ratio measurement discrepancy

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

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

Original Message:
Sent: 10-08-2023 17:15
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

------------------------------
Floyd Gadd RPT
Regina SK
(306) 502-9103

Original Message:
Sent: 10-12-2023 20:02
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

What is exact definition for Inertial Playing Quality? Formula?, How to measure? .Numbers? How it differs from ordinary Feel of Action Touch?

Alexander Brusilovsky


Original Message:
Sent: 10/11/2023 8:03:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-08-2023 22:13
From: David Love
Subject: Action ratio measurement discrepancy

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

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

Original Message:
Sent: 10-08-2023 17:15
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-08-2023 11:37
From: David Love
Subject: Action ratio measurement discrepancy

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

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

Original Message:
Sent: 10-07-2023 23:16
From: Chris Chernobieff
Subject: Action ratio measurement discrepancy

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

------------------------------
Chernobieff Piano Restorations
All the elements are known, and yet no combination there of creates life. Yet we are here.
865-986-7720 (text only please)

Original Message:
Sent: 10-07-2023 10:46
From: David Stanwood
Subject: Action ratio measurement discrepancy

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-06-2023 10:16
From: Scott Cole
Subject: Action ratio measurement discrepancy

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Alexander,

As much as I am not a fan of the Stanwood method because of its inaccuracies. I'll disagree that you cannot predict dynamic qualities by using static measures. You can ball park it. The end product most pianists will be happy with, until they play on something better that is.

-chris

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Alexander,

As much as I am not a fan of the Stanwood method because of its inaccuracies. I'll disagree that you cannot predict dynamic qualities by using static measures. You can ball park it. The end product most pianists will be happy with, until they play on something better that is.

-chris

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Well, when they start making keys out of cast iron I guess we'll have something to worry about.  

Alexander,

As much as I am not a fan of the Stanwood method because of its inaccuracies. I'll disagree that you cannot predict dynamic qualities by using static measures. You can ball park it. The end product most pianists will be happy with, until they play on something better that is.

-chris

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

Well, when they start making keys out of cast iron I guess we'll have something to worry about.  

Alexander,

As much as I am not a fan of the Stanwood method because of its inaccuracies. I'll disagree that you cannot predict dynamic qualities by using static measures. You can ball park it. The end product most pianists will be happy with, until they play on something better that is.

-chris

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

I would be surprised if any of those difference rose to any level of significance. 

Interestingly, and contrary to your assertion,  shorter keys, with less mass, tend to be associated with actions that feel heavier. That's likely because even though they have less mass and therefore a lower MOI, especially when the AR is considered from a fixed point, the AR changes faster as you move away from the end of the key and toward the balance rail. Since we mostly don't play the piano from the end of the key where all these measurements are taken from, the shorter key, with less mass, turns out to have poorer mechanical advantage when the median point of contact between finger and key is taken into consideration.

Wood density, capstan and backcheck differences in comparison are of absolutely no consequence. 

Well, when they start making keys out of cast iron I guess we'll have something to worry about.  

Alexander,

As much as I am not a fan of the Stanwood method because of its inaccuracies. I'll disagree that you cannot predict dynamic qualities by using static measures. You can ball park it. The end product most pianists will be happy with, until they play on something better that is.

-chris

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

I would be surprised if any of those difference rose to any level of significance. 

Interestingly, and contrary to your assertion,  shorter keys, with less mass, tend to be associated with actions that feel heavier. That's likely because even though they have less mass and therefore a lower MOI, especially when the AR is considered from a fixed point, the AR changes faster as you move away from the end of the key and toward the balance rail. Since we mostly don't play the piano from the end of the key where all these measurements are taken from, the shorter key, with less mass, turns out to have poorer mechanical advantage when the median point of contact between finger and key is taken into consideration.

Wood density, capstan and backcheck differences in comparison are of absolutely no consequence. 

Well, when they start making keys out of cast iron I guess we'll have something to worry about.  

Alexander,

As much as I am not a fan of the Stanwood method because of its inaccuracies. I'll disagree that you cannot predict dynamic qualities by using static measures. You can ball park it. The end product most pianists will be happy with, until they play on something better that is.

-chris

And of course the  voicing of the instrument effects playing quality.  Very generally speaking for a given weight/ratio set up a mellow tone will feel heavier than a bright tone in a given instrument.   Then there is the damper action weight and timing that effects playing quality.   I like to think of the main action as the baseball bat and the damper action is the ball being hit.   It gets swept up mid stroke.  

You know, that's a very good question Alexander!   While the hammer weight/ratio combination determines the underlying  and overriding playing quality, the down weight is still part of the piano playing experience.    In my experience pianists notice down weight mostly as they play into the pianissimo ranges.  This makes sense because down weight is measured in the slowly moving hammer and that's closest to the most extreme pianissimo playing mode.    I've observed pianists playing pianos with extremely high down weights and normal inertia quality and they don't notice it at all but other are very sensitive and do notice.    So it's not all about Inertial Playing Quality. 

------------------------------
David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583

Original Message:
Sent: 10-13-2023 14:13
From: Alexander Brusilovsky
Subject: Action ratio measurement discrepancy

David. So , Inertial playing quality and Playing quality are the same things?


Alexander Brusilovsky


Original Message:
Sent: 10/13/2023 11:04:00 AM
From: David Stanwood
Subject: RE: Action ratio measurement discrepancy

Hi Alexander,  There is no unit of "Stanwood Inertial Playing Quality".   The tables given in my October article simply associate dynamic qualities with pairings of Balance Weight and Front Weight  So you need to know how to determine these measures.  You also need to know how to determine Wippen Balance Weight and make corrections if need be.  A careful reading of the article will guide you as to what you need to know to practice this approach.  

Alexander, the concept of inertial playing quality, together with the formulae and the means of measuring, are laid out by David Stanwood in his article on the Stanwood New Action Protocol in the October 2023 Piano Technicians Journal.  Part One of this series appeared in the June 2023 journal.

Inertial playing quality is a component of the feel of action touch.  Stanwood is distinguishing it from what is achieved by merely ensuring that there is enough weight in the key front to produce a target down weight or a target balance weight.  Inertial playing quality takes into account how the leverage of the action interacts with the mass of the hammer. An action can be perfectly balanced for a targeted down weight, but there can be so much mass to be put into motion (for a given leverage) that the pianist still struggles with counterproductive heaviness in the feel of the action. 

I've played a number of Daryl Fandrich pianos balanced with his approach.  They were quite extraordinary as to prep, regulation, and voicing.  My impression was that they were on the lighter side, inertially speaking.   In my October 2023 Journal article I show what I call the Touch Design Selection Guide and give detailed information as to how the table was derived.   If you plug in a FW of 24g-25g for C4 with a 37 BW you get a Light  +1 Inertial Playing Quality with a Wippen Balance Weight level of 9g.   

That's probably because I don't measure inertia. As has been discussed several times, most of the inertia in the system comes from the relationship between the strike weight and the action ratio, leverage, mechanical advantage, strike weight ratio, however you like to think about it. The front weight by itself doesn't tell you anything. But in combination with the balance weight, it tells you about that relationship. 

i have read all of the Fandrich-Rhodes articles. Their exact methodology is proprietary so I can't comment on their precise derivation of the ITF number.  But an analysis of the parameters which produce "an action to die for" agree with my own target of balance weight:front weight relationship (at a specific note-I recall they use F44, I use C40) and also with David Starwood's approach. 

If you set up the action with a balance weight at C40 of say 37 grams (there is some leeway in terms of standards) and a FW of about 24-25 grams and a normal spread of hammer weight from 1-88 you'll have "an action to die for". 

You can lower the inertia by reducing the strike weight (or the action ratio) so that a 37g balance weight is achieved with a lower front weight, say 20 grams. If you want higher inertia then increase the hammer weight so it takes 30 grams of FW to achieve that same BW, or raise the action ratio. If you end up with a FW that is too low you'll have insufficient inertia also known as a "fly away" action. If the FW is too high at that BW then your strike weight is too high for that action ratio and you'll have a high inertia action that fights you (offers too much resistance to acceleration). That's not because of excess lead, it's because of a poor SW:AR relationship which results in excess leads to achieve a your target BW  The excess lead does contribute something to the inertia but it's not the driving force  

Yes it really is that simple. 

I've seen no evidence your measuring inertia. Honestly, from your descriptions it sounds to me like static balancing with changed terminology.

First my system steps off from the Fandrich/Rhodes methodology but it is more inclusive than they were. I suggest reading their 3rd article from the Touch to Die For series. I used a lot from there. As a result,  and by happenstance, a new method for lead placement and amounts was discovered. I call it triangulation because it solves three issues that must be met for inertia requirements. Front Weight is a poor measurement method highlighted by the fact that much more weight is needed by the balance point than at the front of the key to reach the same DW.

Its a major flaw, when you use as a working model, actions from the past, when inertia wasn't understood. They can be good, but they are also lacking. Its one of those things that you dont realize until there is a side by side.

As regards to offerings, that's currently reserved for my clients at this time. I do however plan on taking a couple pianos of mine to shows in the near future to display the new technology.

-chris

There are complications measuring AR but no more than measuring inertia.  How do you figure your center mass? In what point in the stroke are you measuring inertia (it changes), what is the acceleration you're using?  Static measurements can be very useful in determining a basis from which to infer, or calculate, dynamics.  Sure, it's complicated but saying that it is or suggesting that static measurements are "junk in junk out" (the actual expression is "garbage in garbage out") is not only not useful but you've proposed no better method.  

Scott,

The current methods of measuring AR are inaccurate.

With one you are measuring mechanical noise. In the other, you are dealing with variable center of rotations. Compounded by the the added minute variations going from note to note.

So as the old saying goes junk in, junk out.

Inertia in rotational movement is the issue, not static balance. Static measurements create complications as you are seeing.

-chris

Scott, 

I talk about variations in Strike Weight Ratio in the PTjournal March 2000 page 25

Hi everyone,

Using the formula for key ratio, wippen ratio, and hammer ratio, did a set of measurements on a 1930s D and came up with an action ratio of 5.2. (on several keys, including middle and end). I also took measurements with my homemade dip block, which depresses the key 6 mm-that yielded a hammer rise corresponding to an action ratio of about 6.3. My measurement point at the key front was 13 mm in.

I'm more inclined to think it's the higher number, but why would I get such a discrepancy?

thanks!

That might be an interesting experiment,  I could make a key out of steel or brass or just load a key with lead while maintaining the same FW and watch  the inertia values jump up.

-chris

I would be surprised if any of those difference rose to any level of significance. 

Interestingly, and contrary to your assertion,  shorter keys, with less mass, tend to be associated with actions that feel heavier. That's likely because even though they have less mass and therefore a lower MOI, especially when the AR is considered from a fixed point, the AR changes faster as you move away from the end of the key and toward the balance rail. Since we mostly don't play the piano from the end of the key where all these measurements are taken from, the shorter key, with less mass, turns out to have poorer mechanical advantage when the median point of contact between finger and key is taken into consideration.

Wood density, capstan and backcheck differences in comparison are of absolutely no consequence. 

Well, when they start making keys out of cast iron I guess we'll have something to worry about.