Pianotech

I have been asked by a client to improve the touch responsiveness on his Young Chang C-125 G grand piano.  This is essentially a G-185, just shy of 73 inches long.

Every G-185 I service, so far as I can remember does not have wippen-assist springs.  This C-125 G does.  

I once undertook touch-weight improvement on a Samick-built piano, and discovered that the wippen-assist springs were being used to compensate for two design factors.  The springs were to some degree offsetting the effects of some pretty heavy hammers, and they were also serving to address a strategy of minimal key weighting.  I found that increasing the key front weight to the Stanwood maximum still did not put me in a position where I could reasonably remove enough weight from the hammers to achieve a mid-range balance weight without the springs.  Short of replacing the hammers, I could see no way to improve the inertial quality of the action, in terms of the excessive effort being demanded of the user.

The Young-Chang now in front of me is presenting me with a much happier scenario.  I focused my diagnostic work on 5 samples, all C's from C2 to C6. Noting that there was was minimal leading in the keys,  I top-weighted the samples to achieve front weights consistent with what David Stanwood describes as the medium zone (FW#7 in his online documentation), disengaged the wippen-assist springs, and took measurements from which I deduced balance weight.   I came up with the following:

Note      Balance Weight

C2          41

C3          36

C4          33

C5          32.5

C6          32

I then removed the top-weighting, reconnected the wippen-assist springs, and measured up weight and down weight from notes 27 to 53.  Balance weight averaged 43.4 grams, with down-weight averaging 53 grams.  Looking at down weight, there were only 5 outliers that did not fall into the 53 +/- 2grams range.  They came in at 60, 57, 56, 50 and 50.

The wippen-assist springs were set up such that I could access both ends of them, such that I could manipulate them with some precision.  I noted that the springs on the heavy outliers, when unhooked from the spring loops, needed to be strengthened in order to sit at a position parallel to the keys.  Strengthening these springs did not reduce the down weight very much at all.

I have not yet taken comprehensive measurements of key front-weight and strike weight across this range of notes.

Preliminary thoughts:  I am not dealing with monstrously heavy hammers.  A medium-zone strike weight inertial quality can be easily achieved.  Front weight, not accounting for the outliers, is reasonable, though balance weight was significantly higher than what would represent "medium range" in a non-sprung system, given the action ratio that is suggested by my top-weighted measurements.  Something more than spring manipulation will be necessary to bring in the front weight outliers.

My gut instinct is to trash the springs and use leads to establish a medium front weight spec in the key set, but I'm not sure doing so is actually in my customer's best interest.  I do think that adding some additional front weight is necessary, as is ensuring that I have smooth curves in terms of front weight and strike weight.  The questions become, what range of variability do the wippen assist springs actually offer, and If I want a medium range touch responsiveness, as defined by Stanwood, how close to a medium range front weight do I want to get, as measured before the springs are added to the equation.

I am very interested in hearing of any experience you have had in refining touch weight in such a way that integrated front weight adjustment with the fine adjustment of wippen-assist springs.  I have done a bit of this, but has always been in situations where my hammers were too heavy, and where sufficient weight reduction or outright replacement were not options.

I do understand and acknowledge that the protocols I am following are indirect, in regard to the assessment of inertia, that careful work has been done in exploring more direct measurements in this regard, and that this latter approach has been found to be helpful and useful by members of this community.  That being acknowledged, I do also understand the particular trajectory of exploration I am following as having value, and thus do not hesitate to pose questions in this regard.

Thank you for any enlightenment you can provide.

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

Floyd,

I have not done much with wippen springs, however I remember being told that they are intended to be a minimal assist (on the order of 3g), just enough to reduce the initial static friction in the system, and furthermore I was told that most tend to overuse the things, thinking they can make a heavy action lighter. 

I know this does not directly answer anything other than if the design principle is adhered to, any further touchweight adjustments would be done as normal (if this makes any sense).

Peter Grey Piano Doctor 

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

Original Message:
Sent: 07-01-2025 11:51
From: Floyd Gadd
Subject: Wippen Assist Springs

I have been asked by a client to improve the touch responsiveness on his Young Chang C-125 G grand piano.  This is essentially a G-185, just shy of 73 inches long.

Every G-185 I service, so far as I can remember does not have wippen-assist springs.  This C-125 G does.  

I once undertook touch-weight improvement on a Samick-built piano, and discovered that the wippen-assist springs were being used to compensate for two design factors.  The springs were to some degree offsetting the effects of some pretty heavy hammers, and they were also serving to address a strategy of minimal key weighting.  I found that increasing the key front weight to the Stanwood maximum still did not put me in a position where I could reasonably remove enough weight from the hammers to achieve a mid-range balance weight without the springs.  Short of replacing the hammers, I could see no way to improve the inertial quality of the action, in terms of the excessive effort being demanded of the user.

The Young-Chang now in front of me is presenting me with a much happier scenario.  I focused my diagnostic work on 5 samples, all C's from C2 to C6. Noting that there was was minimal leading in the keys,  I top-weighted the samples to achieve front weights consistent with what David Stanwood describes as the medium zone (FW#7 in his online documentation), disengaged the wippen-assist springs, and took measurements from which I deduced balance weight.   I came up with the following:

Note      Balance Weight

C2          41

C3          36

C4          33

C5          32.5

C6          32

I then removed the top-weighting, reconnected the wippen-assist springs, and measured up weight and down weight from notes 27 to 53.  Balance weight averaged 43.4 grams, with down-weight averaging 53 grams.  Looking at down weight, there were only 5 outliers that did not fall into the 53 +/- 2grams range.  They came in at 60, 57, 56, 50 and 50.

The wippen-assist springs were set up such that I could access both ends of them, such that I could manipulate them with some precision.  I noted that the springs on the heavy outliers, when unhooked from the spring loops, needed to be strengthened in order to sit at a position parallel to the keys.  Strengthening these springs did not reduce the down weight very much at all.

I have not yet taken comprehensive measurements of key front-weight and strike weight across this range of notes.

Preliminary thoughts:  I am not dealing with monstrously heavy hammers.  A medium-zone strike weight inertial quality can be easily achieved.  Front weight, not accounting for the outliers, is reasonable, though balance weight was significantly higher than what would represent "medium range" in a non-sprung system, given the action ratio that is suggested by my top-weighted measurements.  Something more than spring manipulation will be necessary to bring in the front weight outliers.

My gut instinct is to trash the springs and use leads to establish a medium front weight spec in the key set, but I'm not sure doing so is actually in my customer's best interest.  I do think that adding some additional front weight is necessary, as is ensuring that I have smooth curves in terms of front weight and strike weight.  The questions become, what range of variability do the wippen assist springs actually offer, and If I want a medium range touch responsiveness, as defined by Stanwood, how close to a medium range front weight do I want to get, as measured before the springs are added to the equation.

I am very interested in hearing of any experience you have had in refining touch weight in such a way that integrated front weight adjustment with the fine adjustment of wippen-assist springs.  I have done a bit of this, but has always been in situations where my hammers were too heavy, and where sufficient weight reduction or outright replacement were not options.

I do understand and acknowledge that the protocols I am following are indirect, in regard to the assessment of inertia, that careful work has been done in exploring more direct measurements in this regard, and that this latter approach has been found to be helpful and useful by members of this community.  That being acknowledged, I do also understand the particular trajectory of exploration I am following as having value, and thus do not hesitate to pose questions in this regard.

Thank you for any enlightenment you can provide.

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

Looking back in the Pianotech archive, I realize that a more basic question I asked about the wippen assist springs back in November of 2022 generated a significant volume of helpful responses.  I'll probably find what I need there.  Peter, I think what I'm seeing there is very consistent with your response.  Thanks for chiming in!

Floyd,

I have not done much with wippen springs, however I remember being told that they are intended to be a minimal assist (on the order of 3g), just enough to reduce the initial static friction in the system, and furthermore I was told that most tend to overuse the things, thinking they can make a heavy action lighter. 

I know this does not directly answer anything other than if the design principle is adhered to, any further touchweight adjustments would be done as normal (if this makes any sense).

Peter Grey Piano Doctor 

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

Original Message:
Sent: 07-01-2025 11:51
From: Floyd Gadd
Subject: Wippen Assist Springs

I have been asked by a client to improve the touch responsiveness on his Young Chang C-125 G grand piano.  This is essentially a G-185, just shy of 73 inches long.

Every G-185 I service, so far as I can remember does not have wippen-assist springs.  This C-125 G does.  

I once undertook touch-weight improvement on a Samick-built piano, and discovered that the wippen-assist springs were being used to compensate for two design factors.  The springs were to some degree offsetting the effects of some pretty heavy hammers, and they were also serving to address a strategy of minimal key weighting.  I found that increasing the key front weight to the Stanwood maximum still did not put me in a position where I could reasonably remove enough weight from the hammers to achieve a mid-range balance weight without the springs.  Short of replacing the hammers, I could see no way to improve the inertial quality of the action, in terms of the excessive effort being demanded of the user.

The Young-Chang now in front of me is presenting me with a much happier scenario.  I focused my diagnostic work on 5 samples, all C's from C2 to C6. Noting that there was was minimal leading in the keys,  I top-weighted the samples to achieve front weights consistent with what David Stanwood describes as the medium zone (FW#7 in his online documentation), disengaged the wippen-assist springs, and took measurements from which I deduced balance weight.   I came up with the following:

Note      Balance Weight

C2          41

C3          36

C4          33

C5          32.5

C6          32

I then removed the top-weighting, reconnected the wippen-assist springs, and measured up weight and down weight from notes 27 to 53.  Balance weight averaged 43.4 grams, with down-weight averaging 53 grams.  Looking at down weight, there were only 5 outliers that did not fall into the 53 +/- 2grams range.  They came in at 60, 57, 56, 50 and 50.

The wippen-assist springs were set up such that I could access both ends of them, such that I could manipulate them with some precision.  I noted that the springs on the heavy outliers, when unhooked from the spring loops, needed to be strengthened in order to sit at a position parallel to the keys.  Strengthening these springs did not reduce the down weight very much at all.

I have not yet taken comprehensive measurements of key front-weight and strike weight across this range of notes.

Preliminary thoughts:  I am not dealing with monstrously heavy hammers.  A medium-zone strike weight inertial quality can be easily achieved.  Front weight, not accounting for the outliers, is reasonable, though balance weight was significantly higher than what would represent "medium range" in a non-sprung system, given the action ratio that is suggested by my top-weighted measurements.  Something more than spring manipulation will be necessary to bring in the front weight outliers.

My gut instinct is to trash the springs and use leads to establish a medium front weight spec in the key set, but I'm not sure doing so is actually in my customer's best interest.  I do think that adding some additional front weight is necessary, as is ensuring that I have smooth curves in terms of front weight and strike weight.  The questions become, what range of variability do the wippen assist springs actually offer, and If I want a medium range touch responsiveness, as defined by Stanwood, how close to a medium range front weight do I want to get, as measured before the springs are added to the equation.

I am very interested in hearing of any experience you have had in refining touch weight in such a way that integrated front weight adjustment with the fine adjustment of wippen-assist springs.  I have done a bit of this, but has always been in situations where my hammers were too heavy, and where sufficient weight reduction or outright replacement were not options.

I do understand and acknowledge that the protocols I am following are indirect, in regard to the assessment of inertia, that careful work has been done in exploring more direct measurements in this regard, and that this latter approach has been found to be helpful and useful by members of this community.  That being acknowledged, I do also understand the particular trajectory of exploration I am following as having value, and thus do not hesitate to pose questions in this regard.

Thank you for any enlightenment you can provide.

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

Floyd,

Did you contact Young Chang first before bringing this to the public? 

What did they say?

-chris

Looking back in the Pianotech archive, I realize that a more basic question I asked about the wippen assist springs back in November of 2022 generated a significant volume of helpful responses.  I'll probably find what I need there.  Peter, I think what I'm seeing there is very consistent with your response.  Thanks for chiming in!

Floyd,

I have not done much with wippen springs, however I remember being told that they are intended to be a minimal assist (on the order of 3g), just enough to reduce the initial static friction in the system, and furthermore I was told that most tend to overuse the things, thinking they can make a heavy action lighter. 

I know this does not directly answer anything other than if the design principle is adhered to, any further touchweight adjustments would be done as normal (if this makes any sense).

Peter Grey Piano Doctor 

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

Original Message:
Sent: 07-01-2025 11:51
From: Floyd Gadd
Subject: Wippen Assist Springs

I have been asked by a client to improve the touch responsiveness on his Young Chang C-125 G grand piano.  This is essentially a G-185, just shy of 73 inches long.

Every G-185 I service, so far as I can remember does not have wippen-assist springs.  This C-125 G does.  

I once undertook touch-weight improvement on a Samick-built piano, and discovered that the wippen-assist springs were being used to compensate for two design factors.  The springs were to some degree offsetting the effects of some pretty heavy hammers, and they were also serving to address a strategy of minimal key weighting.  I found that increasing the key front weight to the Stanwood maximum still did not put me in a position where I could reasonably remove enough weight from the hammers to achieve a mid-range balance weight without the springs.  Short of replacing the hammers, I could see no way to improve the inertial quality of the action, in terms of the excessive effort being demanded of the user.

The Young-Chang now in front of me is presenting me with a much happier scenario.  I focused my diagnostic work on 5 samples, all C's from C2 to C6. Noting that there was was minimal leading in the keys,  I top-weighted the samples to achieve front weights consistent with what David Stanwood describes as the medium zone (FW#7 in his online documentation), disengaged the wippen-assist springs, and took measurements from which I deduced balance weight.   I came up with the following:

Note      Balance Weight

C2          41

C3          36

C4          33

C5          32.5

C6          32

I then removed the top-weighting, reconnected the wippen-assist springs, and measured up weight and down weight from notes 27 to 53.  Balance weight averaged 43.4 grams, with down-weight averaging 53 grams.  Looking at down weight, there were only 5 outliers that did not fall into the 53 +/- 2grams range.  They came in at 60, 57, 56, 50 and 50.

The wippen-assist springs were set up such that I could access both ends of them, such that I could manipulate them with some precision.  I noted that the springs on the heavy outliers, when unhooked from the spring loops, needed to be strengthened in order to sit at a position parallel to the keys.  Strengthening these springs did not reduce the down weight very much at all.

I have not yet taken comprehensive measurements of key front-weight and strike weight across this range of notes.

Preliminary thoughts:  I am not dealing with monstrously heavy hammers.  A medium-zone strike weight inertial quality can be easily achieved.  Front weight, not accounting for the outliers, is reasonable, though balance weight was significantly higher than what would represent "medium range" in a non-sprung system, given the action ratio that is suggested by my top-weighted measurements.  Something more than spring manipulation will be necessary to bring in the front weight outliers.

My gut instinct is to trash the springs and use leads to establish a medium front weight spec in the key set, but I'm not sure doing so is actually in my customer's best interest.  I do think that adding some additional front weight is necessary, as is ensuring that I have smooth curves in terms of front weight and strike weight.  The questions become, what range of variability do the wippen assist springs actually offer, and If I want a medium range touch responsiveness, as defined by Stanwood, how close to a medium range front weight do I want to get, as measured before the springs are added to the equation.

I am very interested in hearing of any experience you have had in refining touch weight in such a way that integrated front weight adjustment with the fine adjustment of wippen-assist springs.  I have done a bit of this, but has always been in situations where my hammers were too heavy, and where sufficient weight reduction or outright replacement were not options.

I do understand and acknowledge that the protocols I am following are indirect, in regard to the assessment of inertia, that careful work has been done in exploring more direct measurements in this regard, and that this latter approach has been found to be helpful and useful by members of this community.  That being acknowledged, I do also understand the particular trajectory of exploration I am following as having value, and thus do not hesitate to pose questions in this regard.

Thank you for any enlightenment you can provide.

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

Touché.

Chris, you have here aptly demonstrated that my words in the post about respecting our suppliers, taken at face value, can fairly be understood to suggest a level of scrutiny that my own routine postings cannot survive.

I here downgrade my estimation of my original post in that thread from "probably overstated my case" to "demonstrably overstated my case."

Floyd,

Did you contact Young Chang first before bringing this to the public? 

What did they say?

-chris

Looking back in the Pianotech archive, I realize that a more basic question I asked about the wippen assist springs back in November of 2022 generated a significant volume of helpful responses.  I'll probably find what I need there.  Peter, I think what I'm seeing there is very consistent with your response.  Thanks for chiming in!

Floyd,

I have not done much with wippen springs, however I remember being told that they are intended to be a minimal assist (on the order of 3g), just enough to reduce the initial static friction in the system, and furthermore I was told that most tend to overuse the things, thinking they can make a heavy action lighter. 

I know this does not directly answer anything other than if the design principle is adhered to, any further touchweight adjustments would be done as normal (if this makes any sense).

Peter Grey Piano Doctor 

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

Original Message:
Sent: 07-01-2025 11:51
From: Floyd Gadd
Subject: Wippen Assist Springs

I have been asked by a client to improve the touch responsiveness on his Young Chang C-125 G grand piano.  This is essentially a G-185, just shy of 73 inches long.

Every G-185 I service, so far as I can remember does not have wippen-assist springs.  This C-125 G does.  

I once undertook touch-weight improvement on a Samick-built piano, and discovered that the wippen-assist springs were being used to compensate for two design factors.  The springs were to some degree offsetting the effects of some pretty heavy hammers, and they were also serving to address a strategy of minimal key weighting.  I found that increasing the key front weight to the Stanwood maximum still did not put me in a position where I could reasonably remove enough weight from the hammers to achieve a mid-range balance weight without the springs.  Short of replacing the hammers, I could see no way to improve the inertial quality of the action, in terms of the excessive effort being demanded of the user.

The Young-Chang now in front of me is presenting me with a much happier scenario.  I focused my diagnostic work on 5 samples, all C's from C2 to C6. Noting that there was was minimal leading in the keys,  I top-weighted the samples to achieve front weights consistent with what David Stanwood describes as the medium zone (FW#7 in his online documentation), disengaged the wippen-assist springs, and took measurements from which I deduced balance weight.   I came up with the following:

Note      Balance Weight

C2          41

C3          36

C4          33

C5          32.5

C6          32

I then removed the top-weighting, reconnected the wippen-assist springs, and measured up weight and down weight from notes 27 to 53.  Balance weight averaged 43.4 grams, with down-weight averaging 53 grams.  Looking at down weight, there were only 5 outliers that did not fall into the 53 +/- 2grams range.  They came in at 60, 57, 56, 50 and 50.

The wippen-assist springs were set up such that I could access both ends of them, such that I could manipulate them with some precision.  I noted that the springs on the heavy outliers, when unhooked from the spring loops, needed to be strengthened in order to sit at a position parallel to the keys.  Strengthening these springs did not reduce the down weight very much at all.

I have not yet taken comprehensive measurements of key front-weight and strike weight across this range of notes.

Preliminary thoughts:  I am not dealing with monstrously heavy hammers.  A medium-zone strike weight inertial quality can be easily achieved.  Front weight, not accounting for the outliers, is reasonable, though balance weight was significantly higher than what would represent "medium range" in a non-sprung system, given the action ratio that is suggested by my top-weighted measurements.  Something more than spring manipulation will be necessary to bring in the front weight outliers.

My gut instinct is to trash the springs and use leads to establish a medium front weight spec in the key set, but I'm not sure doing so is actually in my customer's best interest.  I do think that adding some additional front weight is necessary, as is ensuring that I have smooth curves in terms of front weight and strike weight.  The questions become, what range of variability do the wippen assist springs actually offer, and If I want a medium range touch responsiveness, as defined by Stanwood, how close to a medium range front weight do I want to get, as measured before the springs are added to the equation.

I am very interested in hearing of any experience you have had in refining touch weight in such a way that integrated front weight adjustment with the fine adjustment of wippen-assist springs.  I have done a bit of this, but has always been in situations where my hammers were too heavy, and where sufficient weight reduction or outright replacement were not options.

I do understand and acknowledge that the protocols I am following are indirect, in regard to the assessment of inertia, that careful work has been done in exploring more direct measurements in this regard, and that this latter approach has been found to be helpful and useful by members of this community.  That being acknowledged, I do also understand the particular trajectory of exploration I am following as having value, and thus do not hesitate to pose questions in this regard.

Thank you for any enlightenment you can provide.

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