Pianotech

Does anyone recall any recent PTJ articles about drop regulation in
grand pianos?

There was a recent exchange here about concepts and techniques that I
found interesting. The suggestion was to move away from the old rule of
1/16" below letoff and regulate drop to be simultaneous with contact of
the jack with the letoff button. I have tried this with good results,
but then drop appears to be somewhat deeper than the usual recommendation.

Has anyone had a musician actually respond to a change in drop
regulation (aside from getting it normal specifications or "in the
ballpark")?

A technician's board or forum exchange might make a decent PTJ article
(if it hasn't already been done).

Does anyone recall any recent PTJ articles about drop regulation in
grand pianos?

There was a recent exchange here about concepts and techniques that I
found interesting. The suggestion was to move away from the old rule of
1/16" below letoff and regulate drop to be simultaneous with contact of
the jack with the letoff button. I have tried this with good results,
but then drop appears to be somewhat deeper than the usual recommendation.

Has anyone had a musician actually respond to a change in drop
regulation (aside from getting it normal specifications or "in the
ballpark")?

A technician's board or forum exchange might make a decent PTJ article
(if it hasn't already been done).

You might want to search for regulate drop (or similar wording) in the Journal Index. I don't think there is any article devoted specifically to drop, but it is certainly addressed as part of grand regulation in lots and lots of articles.

On the question of simultaneity of jack tender and drop screw contact, you need to bear in mind that adjusting the alignment of the jack to knuckle simultaneously changes the position of the jack tender relative to the let off button. It won't affect when let off occurs, but it will affect when contact happens. A jack farther under the knuckle will contact earlier.

So you have to start with good consistent jack alignment to get consistent simultaneity of drop and jack contact.

I think simultaneity makes a big difference, but I'm not sure absolute simultaneity is possible or desirable in all cases. I do believe the hammer needs to drop below the point of let off by at least 1 mm, preferably 1.5 mm, as an absolute. If that means the drop screw is contacted a smidge ahead of the jack tender, I accept it.

It is necessary to talk about drop only in terms of how far the hammer drops during a carefully controlled keystroke just after escapement. Drop is not the position of the hammer when the key is fully depressed. The hammer needs to be below the level of the string (obviously) when the key is fully depressed, but that is achieved by adjusting aftertouch. During the controlled key stroke, the hammer should fall 1 - 1.5 mm, then rise as much as 1 mm during aftertouch. If it doesn't rise at all, there isn't enough aftertouch.

In my method of setting drop, I have already refined let off in the piano to be 1 mm. With the action on the bench, I depress one key fully, holding it down so that the hammer is held in the air something between the drop  position and the let off position (I am not worried about replicating key dip in the piano - this is just a reference point for comparison purposes).

I now depress the key next to the reference key until I feel drop contact. I make sure exactly where that is, with a sensitive finger moving up and down until I am centered in that spot. I also note whether that spot feels firm and definite or vague and spongy. If the former, I am close to simultaneity, if the latter the two contacts are separate (and I try to feel how far  apart). With the key held at the firmest spot (the rep spring is much stronger than the jack spring, so that will be drop contact) I note how high the hammer is relative to the reference neighbor.

I now press slowly through let off, noting how high the hammer moves to let off and how far it drop in the limited/controlled key stroke (just barely allowing let off to occur and holding the key there). I have three points I am comparing: the initial drop screw contact, the high point at let off, and the drop after let off. The distance between low and high point should be about 3 mm, between high and drop point about 1.5 mm.

Typically drop will have started off low (drop contact early), and I will raise the screw until I meet my target spec, while also feeling for firm simultaneity. Sometimes I find that actual simultaneity will result in the hammer barely dropping at all, which is not a good feel. In that case I compromise to make there be a positive drop of at least 1 mm, accepting a wee bit of sponginess - or I might investigate whether the jack is misplaced relative to the knuckle.

I've been doing it this way for decades, and highly accomplished pianists (including myself) seem to be consistently pleased with the results.

I'll add that I hate pianos with early drop contact. They play much heavier because you are compressing that rep spring a lot at the bottom of the keystroke right when you are trying to finesse key speed for control of dynamics. And almost every piano I come across has drop contact early. Obviously that is something that the majority of piano technicians do.

Does anyone recall any recent PTJ articles about drop regulation in
grand pianos?

There was a recent exchange here about concepts and techniques that I
found interesting. The suggestion was to move away from the old rule of
1/16" below letoff and regulate drop to be simultaneous with contact of
the jack with the letoff button. I have tried this with good results,
but then drop appears to be somewhat deeper than the usual recommendation.

Has anyone had a musician actually respond to a change in drop
regulation (aside from getting it normal specifications or "in the
ballpark")?

A technician's board or forum exchange might make a decent PTJ article
(if it hasn't already been done).

I was doing some regulation yesterday on a 1965 Baldwin L, which received new hammers fairly recently.  I custom-bored the hammers, taking into account flange center pin height and string height, so I think my bore length is right.  I have set up the action for simultaneous contact of the jack/button and the rep lever/screw.  Drop is lower than I want it to be.  I'm trying to think through how to maintain simultaneous contact and still raise my drop.  I am picturing a scenario of having the jack further forward at rest, which if taken too far could lead to skipping jacks.  It has occurred to me that messing with the action spread could be a part of this puzzle.  I'm not sitting with the action in front of me right now.  Am I mis-imagining what is at play?

You might want to search for regulate drop (or similar wording) in the Journal Index. I don't think there is any article devoted specifically to drop, but it is certainly addressed as part of grand regulation in lots and lots of articles.

On the question of simultaneity of jack tender and drop screw contact, you need to bear in mind that adjusting the alignment of the jack to knuckle simultaneously changes the position of the jack tender relative to the let off button. It won't affect when let off occurs, but it will affect when contact happens. A jack farther under the knuckle will contact earlier.

So you have to start with good consistent jack alignment to get consistent simultaneity of drop and jack contact.

I think simultaneity makes a big difference, but I'm not sure absolute simultaneity is possible or desirable in all cases. I do believe the hammer needs to drop below the point of let off by at least 1 mm, preferably 1.5 mm, as an absolute. If that means the drop screw is contacted a smidge ahead of the jack tender, I accept it.

It is necessary to talk about drop only in terms of how far the hammer drops during a carefully controlled keystroke just after escapement. Drop is not the position of the hammer when the key is fully depressed. The hammer needs to be below the level of the string (obviously) when the key is fully depressed, but that is achieved by adjusting aftertouch. During the controlled key stroke, the hammer should fall 1 - 1.5 mm, then rise as much as 1 mm during aftertouch. If it doesn't rise at all, there isn't enough aftertouch.

In my method of setting drop, I have already refined let off in the piano to be 1 mm. With the action on the bench, I depress one key fully, holding it down so that the hammer is held in the air something between the drop  position and the let off position (I am not worried about replicating key dip in the piano - this is just a reference point for comparison purposes).

I now depress the key next to the reference key until I feel drop contact. I make sure exactly where that is, with a sensitive finger moving up and down until I am centered in that spot. I also note whether that spot feels firm and definite or vague and spongy. If the former, I am close to simultaneity, if the latter the two contacts are separate (and I try to feel how far  apart). With the key held at the firmest spot (the rep spring is much stronger than the jack spring, so that will be drop contact) I note how high the hammer is relative to the reference neighbor.

I now press slowly through let off, noting how high the hammer moves to let off and how far it drop in the limited/controlled key stroke (just barely allowing let off to occur and holding the key there). I have three points I am comparing: the initial drop screw contact, the high point at let off, and the drop after let off. The distance between low and high point should be about 3 mm, between high and drop point about 1.5 mm.

Typically drop will have started off low (drop contact early), and I will raise the screw until I meet my target spec, while also feeling for firm simultaneity. Sometimes I find that actual simultaneity will result in the hammer barely dropping at all, which is not a good feel. In that case I compromise to make there be a positive drop of at least 1 mm, accepting a wee bit of sponginess - or I might investigate whether the jack is misplaced relative to the knuckle.

I've been doing it this way for decades, and highly accomplished pianists (including myself) seem to be consistently pleased with the results.

I'll add that I hate pianos with early drop contact. They play much heavier because you are compressing that rep spring a lot at the bottom of the keystroke right when you are trying to finesse key speed for control of dynamics. And almost every piano I come across has drop contact early. Obviously that is something that the majority of piano technicians do.

Does anyone recall any recent PTJ articles about drop regulation in
grand pianos?

There was a recent exchange here about concepts and techniques that I
found interesting. The suggestion was to move away from the old rule of
1/16" below letoff and regulate drop to be simultaneous with contact of
the jack with the letoff button. I have tried this with good results,
but then drop appears to be somewhat deeper than the usual recommendation.

Has anyone had a musician actually respond to a change in drop
regulation (aside from getting it normal specifications or "in the
ballpark")?

A technician's board or forum exchange might make a decent PTJ article
(if it hasn't already been done).

To be honest, I don't know what effect spread has on jack/drop simultaneity, but it seems like it should have an impact. If the wippen rail is fairly easily movable, I'd do some experimentation. I do think changing geometry as in changing knuckle distance (retaining original wippens) seems to have an effect.

Are you dealing with original Baldwin wippens, non-butterfly? I have found those problematic particularly in trying to set spring strength well. If I set normally to have a fairly rapid but not jerky rise (no bounce on the top), I find that when tripping jacks, the rep lever doesn't support the hammer well (ie, the hammer drops so the jack won't return under it until I leave far too large a gap between the jack top and the rep lever top surface).

I've only really followed this design consistently on two Baldwin grands, and they seem to repeat fine when the slow and careful jack tripping test would indicate they shouldn't. 

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

Original Message:
Sent: 04-06-2023 21:30
From: Floyd Gadd
Subject: Drop regulation

I was doing some regulation yesterday on a 1965 Baldwin L, which received new hammers fairly recently.  I custom-bored the hammers, taking into account flange center pin height and string height, so I think my bore length is right.  I have set up the action for simultaneous contact of the jack/button and the rep lever/screw.  Drop is lower than I want it to be.  I'm trying to think through how to maintain simultaneous contact and still raise my drop.  I am picturing a scenario of having the jack further forward at rest, which if taken too far could lead to skipping jacks.  It has occurred to me that messing with the action spread could be a part of this puzzle.  I'm not sitting with the action in front of me right now.  Am I mis-imagining what is at play?

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

Original Message:
Sent: 04-06-2023 18:50
From: Fred Sturm
Subject: Drop regulation

You might want to search for regulate drop (or similar wording) in the Journal Index. I don't think there is any article devoted specifically to drop, but it is certainly addressed as part of grand regulation in lots and lots of articles.

On the question of simultaneity of jack tender and drop screw contact, you need to bear in mind that adjusting the alignment of the jack to knuckle simultaneously changes the position of the jack tender relative to the let off button. It won't affect when let off occurs, but it will affect when contact happens. A jack farther under the knuckle will contact earlier.

So you have to start with good consistent jack alignment to get consistent simultaneity of drop and jack contact.

I think simultaneity makes a big difference, but I'm not sure absolute simultaneity is possible or desirable in all cases. I do believe the hammer needs to drop below the point of let off by at least 1 mm, preferably 1.5 mm, as an absolute. If that means the drop screw is contacted a smidge ahead of the jack tender, I accept it.

It is necessary to talk about drop only in terms of how far the hammer drops during a carefully controlled keystroke just after escapement. Drop is not the position of the hammer when the key is fully depressed. The hammer needs to be below the level of the string (obviously) when the key is fully depressed, but that is achieved by adjusting aftertouch. During the controlled key stroke, the hammer should fall 1 - 1.5 mm, then rise as much as 1 mm during aftertouch. If it doesn't rise at all, there isn't enough aftertouch.

In my method of setting drop, I have already refined let off in the piano to be 1 mm. With the action on the bench, I depress one key fully, holding it down so that the hammer is held in the air something between the drop  position and the let off position (I am not worried about replicating key dip in the piano - this is just a reference point for comparison purposes).

I now depress the key next to the reference key until I feel drop contact. I make sure exactly where that is, with a sensitive finger moving up and down until I am centered in that spot. I also note whether that spot feels firm and definite or vague and spongy. If the former, I am close to simultaneity, if the latter the two contacts are separate (and I try to feel how far  apart). With the key held at the firmest spot (the rep spring is much stronger than the jack spring, so that will be drop contact) I note how high the hammer is relative to the reference neighbor.

I now press slowly through let off, noting how high the hammer moves to let off and how far it drop in the limited/controlled key stroke (just barely allowing let off to occur and holding the key there). I have three points I am comparing: the initial drop screw contact, the high point at let off, and the drop after let off. The distance between low and high point should be about 3 mm, between high and drop point about 1.5 mm.

Typically drop will have started off low (drop contact early), and I will raise the screw until I meet my target spec, while also feeling for firm simultaneity. Sometimes I find that actual simultaneity will result in the hammer barely dropping at all, which is not a good feel. In that case I compromise to make there be a positive drop of at least 1 mm, accepting a wee bit of sponginess - or I might investigate whether the jack is misplaced relative to the knuckle.

I've been doing it this way for decades, and highly accomplished pianists (including myself) seem to be consistently pleased with the results.

I'll add that I hate pianos with early drop contact. They play much heavier because you are compressing that rep spring a lot at the bottom of the keystroke right when you are trying to finesse key speed for control of dynamics. And almost every piano I come across has drop contact early. Obviously that is something that the majority of piano technicians do.

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

Original Message:
Sent: 04-02-2023 07:54
From: Edward Foote
Subject: Drop regulation

Original Message:
Sent: 4/2/2023 1:49:00 AM
From: Blaine Hebert
Subject: Drop regulation

Does anyone recall any recent PTJ articles about drop regulation in
grand pianos?

There was a recent exchange here about concepts and techniques that I
found interesting. The suggestion was to move away from the old rule of
1/16" below letoff and regulate drop to be simultaneous with contact of
the jack with the letoff button. I have tried this with good results,
but then drop appears to be somewhat deeper than the usual recommendation.

Has anyone had a musician actually respond to a change in drop
regulation (aside from getting it normal specifications or "in the
ballpark")?

A technician's board or forum exchange might make a decent PTJ article
(if it hasn't already been done).

Thank you, Fred.

Spread does not affect jack/drop simultaneity, but raising drop and trying to maintain simultaneity will result in decreasing the degree to which the jack is inserted under the knuckle at rest.  This could result, potentially, in skipping jacks.  My thought was that increasing spread would change the relationship between the jack and the knuckle such that a greater degree of insertion is achieved.

I've just been looking at Jim Ialeggio's article on spread in the April 19 journal, and it becomes evident that the manouver I am proposing would decrease the safety margin that needs to be a part of the spread calculation.  Too much spread moves the action into a dysfunctional mode.  I will need to take a very close look at how much margin I have to work with.

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

Original Message:
Sent: 04-09-2023 19:31
From: Fred Sturm
Subject: Drop regulation

To be honest, I don't know what effect spread has on jack/drop simultaneity, but it seems like it should have an impact. If the wippen rail is fairly easily movable, I'd do some experimentation. I do think changing geometry as in changing knuckle distance (retaining original wippens) seems to have an effect.

Are you dealing with original Baldwin wippens, non-butterfly? I have found those problematic particularly in trying to set spring strength well. If I set normally to have a fairly rapid but not jerky rise (no bounce on the top), I find that when tripping jacks, the rep lever doesn't support the hammer well (ie, the hammer drops so the jack won't return under it until I leave far too large a gap between the jack top and the rep lever top surface).

I've only really followed this design consistently on two Baldwin grands, and they seem to repeat fine when the slow and careful jack tripping test would indicate they shouldn't. 

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

Original Message:
Sent: 04-06-2023 21:30
From: Floyd Gadd
Subject: Drop regulation

I was doing some regulation yesterday on a 1965 Baldwin L, which received new hammers fairly recently.  I custom-bored the hammers, taking into account flange center pin height and string height, so I think my bore length is right.  I have set up the action for simultaneous contact of the jack/button and the rep lever/screw.  Drop is lower than I want it to be.  I'm trying to think through how to maintain simultaneous contact and still raise my drop.  I am picturing a scenario of having the jack further forward at rest, which if taken too far could lead to skipping jacks.  It has occurred to me that messing with the action spread could be a part of this puzzle.  I'm not sitting with the action in front of me right now.  Am I mis-imagining what is at play?

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

Original Message:
Sent: 04-06-2023 18:50
From: Fred Sturm
Subject: Drop regulation

You might want to search for regulate drop (or similar wording) in the Journal Index. I don't think there is any article devoted specifically to drop, but it is certainly addressed as part of grand regulation in lots and lots of articles.

On the question of simultaneity of jack tender and drop screw contact, you need to bear in mind that adjusting the alignment of the jack to knuckle simultaneously changes the position of the jack tender relative to the let off button. It won't affect when let off occurs, but it will affect when contact happens. A jack farther under the knuckle will contact earlier.

So you have to start with good consistent jack alignment to get consistent simultaneity of drop and jack contact.

I think simultaneity makes a big difference, but I'm not sure absolute simultaneity is possible or desirable in all cases. I do believe the hammer needs to drop below the point of let off by at least 1 mm, preferably 1.5 mm, as an absolute. If that means the drop screw is contacted a smidge ahead of the jack tender, I accept it.

It is necessary to talk about drop only in terms of how far the hammer drops during a carefully controlled keystroke just after escapement. Drop is not the position of the hammer when the key is fully depressed. The hammer needs to be below the level of the string (obviously) when the key is fully depressed, but that is achieved by adjusting aftertouch. During the controlled key stroke, the hammer should fall 1 - 1.5 mm, then rise as much as 1 mm during aftertouch. If it doesn't rise at all, there isn't enough aftertouch.

In my method of setting drop, I have already refined let off in the piano to be 1 mm. With the action on the bench, I depress one key fully, holding it down so that the hammer is held in the air something between the drop  position and the let off position (I am not worried about replicating key dip in the piano - this is just a reference point for comparison purposes).

I now depress the key next to the reference key until I feel drop contact. I make sure exactly where that is, with a sensitive finger moving up and down until I am centered in that spot. I also note whether that spot feels firm and definite or vague and spongy. If the former, I am close to simultaneity, if the latter the two contacts are separate (and I try to feel how far  apart). With the key held at the firmest spot (the rep spring is much stronger than the jack spring, so that will be drop contact) I note how high the hammer is relative to the reference neighbor.

I now press slowly through let off, noting how high the hammer moves to let off and how far it drop in the limited/controlled key stroke (just barely allowing let off to occur and holding the key there). I have three points I am comparing: the initial drop screw contact, the high point at let off, and the drop after let off. The distance between low and high point should be about 3 mm, between high and drop point about 1.5 mm.

Typically drop will have started off low (drop contact early), and I will raise the screw until I meet my target spec, while also feeling for firm simultaneity. Sometimes I find that actual simultaneity will result in the hammer barely dropping at all, which is not a good feel. In that case I compromise to make there be a positive drop of at least 1 mm, accepting a wee bit of sponginess - or I might investigate whether the jack is misplaced relative to the knuckle.

I've been doing it this way for decades, and highly accomplished pianists (including myself) seem to be consistently pleased with the results.

I'll add that I hate pianos with early drop contact. They play much heavier because you are compressing that rep spring a lot at the bottom of the keystroke right when you are trying to finesse key speed for control of dynamics. And almost every piano I come across has drop contact early. Obviously that is something that the majority of piano technicians do.

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

Original Message:
Sent: 04-02-2023 07:54
From: Edward Foote
Subject: Drop regulation

Original Message:
Sent: 4/2/2023 1:49:00 AM
From: Blaine Hebert
Subject: Drop regulation

Does anyone recall any recent PTJ articles about drop regulation in
grand pianos?

There was a recent exchange here about concepts and techniques that I
found interesting. The suggestion was to move away from the old rule of
1/16" below letoff and regulate drop to be simultaneous with contact of
the jack with the letoff button. I have tried this with good results,
but then drop appears to be somewhat deeper than the usual recommendation.

Has anyone had a musician actually respond to a change in drop
regulation (aside from getting it normal specifications or "in the
ballpark")?

A technician's board or forum exchange might make a decent PTJ article
(if it hasn't already been done).

My last post did not take into account the need to lower the regulating button to compensate for the new relationship between the jack and the knuckle.

I am now thinking the first step is to decrease spread, which has no negative effect on the safety margin.  With spread decreased, the engagement of the jack/regulation button needs to be retarded to correct let-off.  Achieving simultaneity in this scenario requires raising drop.  This also, however, still decreases the insertion of the jack under the knuckle at rest.  Repositioning the jack to a proper depth will again accelerate let-off.  Maybe only experimentation will tell me whether I'm up against a zero-sum game.

Thank you, Fred.

Spread does not affect jack/drop simultaneity, but raising drop and trying to maintain simultaneity will result in decreasing the degree to which the jack is inserted under the knuckle at rest.  This could result, potentially, in skipping jacks.  My thought was that increasing spread would change the relationship between the jack and the knuckle such that a greater degree of insertion is achieved.

I've just been looking at Jim Ialeggio's article on spread in the April 19 journal, and it becomes evident that the manouver I am proposing would decrease the safety margin that needs to be a part of the spread calculation.  Too much spread moves the action into a dysfunctional mode.  I will need to take a very close look at how much margin I have to work with.

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

Original Message:
Sent: 04-09-2023 19:31
From: Fred Sturm
Subject: Drop regulation

To be honest, I don't know what effect spread has on jack/drop simultaneity, but it seems like it should have an impact. If the wippen rail is fairly easily movable, I'd do some experimentation. I do think changing geometry as in changing knuckle distance (retaining original wippens) seems to have an effect.

Are you dealing with original Baldwin wippens, non-butterfly? I have found those problematic particularly in trying to set spring strength well. If I set normally to have a fairly rapid but not jerky rise (no bounce on the top), I find that when tripping jacks, the rep lever doesn't support the hammer well (ie, the hammer drops so the jack won't return under it until I leave far too large a gap between the jack top and the rep lever top surface).

I've only really followed this design consistently on two Baldwin grands, and they seem to repeat fine when the slow and careful jack tripping test would indicate they shouldn't. 

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

Original Message:
Sent: 04-06-2023 21:30
From: Floyd Gadd
Subject: Drop regulation

I was doing some regulation yesterday on a 1965 Baldwin L, which received new hammers fairly recently.  I custom-bored the hammers, taking into account flange center pin height and string height, so I think my bore length is right.  I have set up the action for simultaneous contact of the jack/button and the rep lever/screw.  Drop is lower than I want it to be.  I'm trying to think through how to maintain simultaneous contact and still raise my drop.  I am picturing a scenario of having the jack further forward at rest, which if taken too far could lead to skipping jacks.  It has occurred to me that messing with the action spread could be a part of this puzzle.  I'm not sitting with the action in front of me right now.  Am I mis-imagining what is at play?

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

Original Message:
Sent: 04-06-2023 18:50
From: Fred Sturm
Subject: Drop regulation

You might want to search for regulate drop (or similar wording) in the Journal Index. I don't think there is any article devoted specifically to drop, but it is certainly addressed as part of grand regulation in lots and lots of articles.

On the question of simultaneity of jack tender and drop screw contact, you need to bear in mind that adjusting the alignment of the jack to knuckle simultaneously changes the position of the jack tender relative to the let off button. It won't affect when let off occurs, but it will affect when contact happens. A jack farther under the knuckle will contact earlier.

So you have to start with good consistent jack alignment to get consistent simultaneity of drop and jack contact.

I think simultaneity makes a big difference, but I'm not sure absolute simultaneity is possible or desirable in all cases. I do believe the hammer needs to drop below the point of let off by at least 1 mm, preferably 1.5 mm, as an absolute. If that means the drop screw is contacted a smidge ahead of the jack tender, I accept it.

It is necessary to talk about drop only in terms of how far the hammer drops during a carefully controlled keystroke just after escapement. Drop is not the position of the hammer when the key is fully depressed. The hammer needs to be below the level of the string (obviously) when the key is fully depressed, but that is achieved by adjusting aftertouch. During the controlled key stroke, the hammer should fall 1 - 1.5 mm, then rise as much as 1 mm during aftertouch. If it doesn't rise at all, there isn't enough aftertouch.

In my method of setting drop, I have already refined let off in the piano to be 1 mm. With the action on the bench, I depress one key fully, holding it down so that the hammer is held in the air something between the drop  position and the let off position (I am not worried about replicating key dip in the piano - this is just a reference point for comparison purposes).

I now depress the key next to the reference key until I feel drop contact. I make sure exactly where that is, with a sensitive finger moving up and down until I am centered in that spot. I also note whether that spot feels firm and definite or vague and spongy. If the former, I am close to simultaneity, if the latter the two contacts are separate (and I try to feel how far  apart). With the key held at the firmest spot (the rep spring is much stronger than the jack spring, so that will be drop contact) I note how high the hammer is relative to the reference neighbor.

I now press slowly through let off, noting how high the hammer moves to let off and how far it drop in the limited/controlled key stroke (just barely allowing let off to occur and holding the key there). I have three points I am comparing: the initial drop screw contact, the high point at let off, and the drop after let off. The distance between low and high point should be about 3 mm, between high and drop point about 1.5 mm.

Typically drop will have started off low (drop contact early), and I will raise the screw until I meet my target spec, while also feeling for firm simultaneity. Sometimes I find that actual simultaneity will result in the hammer barely dropping at all, which is not a good feel. In that case I compromise to make there be a positive drop of at least 1 mm, accepting a wee bit of sponginess - or I might investigate whether the jack is misplaced relative to the knuckle.

I've been doing it this way for decades, and highly accomplished pianists (including myself) seem to be consistently pleased with the results.

I'll add that I hate pianos with early drop contact. They play much heavier because you are compressing that rep spring a lot at the bottom of the keystroke right when you are trying to finesse key speed for control of dynamics. And almost every piano I come across has drop contact early. Obviously that is something that the majority of piano technicians do.

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

Original Message:
Sent: 04-02-2023 07:54
From: Edward Foote
Subject: Drop regulation

Original Message:
Sent: 4/2/2023 1:49:00 AM
From: Blaine Hebert
Subject: Drop regulation

Does anyone recall any recent PTJ articles about drop regulation in
grand pianos?

There was a recent exchange here about concepts and techniques that I
found interesting. The suggestion was to move away from the old rule of
1/16" below letoff and regulate drop to be simultaneous with contact of
the jack with the letoff button. I have tried this with good results,
but then drop appears to be somewhat deeper than the usual recommendation.

Has anyone had a musician actually respond to a change in drop
regulation (aside from getting it normal specifications or "in the
ballpark")?

A technician's board or forum exchange might make a decent PTJ article
(if it hasn't already been done).