CAUT

I am taking some time this summer to better study our 1970 Steinway D, which no one, including myself, is entirely happy with in term of action or tone. The touchweight is heavy (53-60g) and sluggish (6 leads in #1 key). But what I've also discovered is that the capstans are significantly distal (maybe 2-4mm) of the center of the wippen heel. I never noticed this before, even when replacing reps in a big rush about 2 years ago. Anyway, I pulled out the original repetitions and they're exactly the same as the Steinway replacements in terms of wippen heel location (of course the jack center is moved back a little on the new ones to accommodate the 17mm knuckle location). New Steinway-hung hammers about 3 years ago. Anyway, when the capstans meet the wippen heel, the back edge of the capstan is aligned with the back edge of the heel felt, not at all at the center "hump" with reinforced felt. I'm thinking this piano was manufactured this way in 1970, had an improperly-located capstan line, and this might explain why no one ever liked it much, from what I hear. I'm considering moving the capstans forward to meet the center of the heels. Action ratio using Dale Erwin's 6mm gauge is about 5.8. Is there anything further I should consider? I mean, Steinway capstans should interface with the middle of the heel, correct? No ifs, ands, or buts? Thanks in advance for all help. I am at the front edge of my knowledge and shop skills when considering moving capstans and changing something this fundamental on a piano like a Steinway, but am thinking I'm on the right track here. -- Paul Milesi Staff Piano Technician Howard University Department of Music Washington, DC (202) 806-4565 University Shop/Office (202) 246-3136 Cell/Text paul.milesi@howard.edu

Paul,

I'll say this.

University pianists make what needs to happen with they are given regardless. They quickly learn of the strengths and weaknesses of pianos that come within the domain of their particular expertise, especially a Steinway D that was made in 1970 and is located on a performance state. Steinway knows such things as well, and long before the rest of the majority.

A 1970 Steinway D is a very old piano. It is what is until someone makes it into another whole thing.

If you are looking at a huge awaking in piano technology, go ahead, or have your university invest in a Steinway D that has just been born by Steinway and never look back.

As Joe Garrett says from time to time on the Piano Tech Archives, "That's my take on it."

-------------------------------------------
Keith McGavern, RPT
Shawnee, Oklahoma, USA
tune-repair@allegiance.tv

Original Message:
Sent: 07-02-2012 15:29
From: Paul Milesi
...  I am at the front edge of my knowledge and
shop skills when considering moving capstans and changing something this
fundamental on a piano like a Steinway, but am thinking I'm on the right
track here. ...

Hi Paul,

One good thing about CAUT work is that we get to see the same pianos over and over, tweak things, and even experiment a bit. I've learned a lot from other people, classes and seminars, as well as from the CAUT list, but I'd have to say that trial and error has to be one of my top "teachers".

It's a simple matter to take out a few sample keys (2 or 3 maybe) and move the capstans, replace the stack and remeasure your action ratio. There's a lot more to it than this, of course, because you have to regulate the keys, etc. but it's an easy way to "get your feet wet". You can easily put things back the way they were, and you're only out a few minutes of your time. This has been invaluable to me; rather than obsess over it, ask everyone I know, (which is not a bad thing, but does take time) and read everything I can about it, I sometimes just do it. In ten minutes or so you may have your answer. (or 10,000 ways NOT to do it! - Edison...:-)

Regards,
Jim

-------------------------------------------
James Busby
Mt Pleasant UT
801-422-3400
-------------------------------------------






I am taking some time this summer to better study our 1970 Steinway D, which
no one, including myself, is entirely happy with in term of action or tone.
The touchweight is heavy (53-60g) and sluggish (6 leads in #1 key). But
what I've also discovered is that the capstans are significantly distal
(maybe 2-4mm) of the center of the wippen heel. I never noticed this
before, even when replacing reps in a big rush about 2 years ago. Anyway, I
pulled out the original repetitions and they're exactly the same as the
Steinway replacements in terms of wippen heel location (of course the jack
center is moved back a little on the new ones to accommodate the 17mm
knuckle location). New Steinway-hung hammers about 3 years ago.

Anyway, when the capstans meet the wippen heel, the back edge of the capstan
is aligned with the back edge of the heel felt, not at all at the center
"hump" with reinforced felt. I'm thinking this piano was manufactured this
way in 1970, had an improperly-located capstan line, and this might explain
why no one ever liked it much, from what I hear. I'm considering moving the
capstans forward to meet the center of the heels. Action ratio using Dale
Erwin's 6mm gauge is about 5.8. Is there anything further I should
consider? I mean, Steinway capstans should interface with the middle of the
heel, correct? No ifs, ands, or buts?

Thanks in advance for all help. I am at the front edge of my knowledge and
shop skills when considering moving capstans and changing something this
fundamental on a piano like a Steinway, but am thinking I'm on the right
track here.
--
Paul Milesi

I agree with Jim, try it and see what happens (I wouldn't count on capstan position relative to the wipp cushions as a guide - maybe it was centered on the designer's drawing, but you don't know what was changed to make it not so, whether it is the capstan position that is "right" or maybe the action was shifted on the stack in its initial placement, yadda, yadda). Remove a couple capstans and use a "capstan boat" to experiment. A piece of wood the width of a key, with a couple pieces of veneer glued to its sides protruding downward, so as to hug the sides of the key. A cut off capstan inserted in the wood, capable of a bit of adjustment (cut off so it is short enough to just thread into the boat).

Best to have the rest of the keys removed, then place your samples on the keyframe and add the stack. Mark the original position of the capstans on the side of the key, and mark a line on your capstan boat to correspond with the middle of its capstan. Now move the capstan boat to a few positions and measure the results.

Besides moving capstans, another alternative to consider is turbo-wipps - with adjustable springs. This can allow you to reduce DW without adding lead, possibly even removing lead, though you don't want to go overboard with spring strength. 15 grams reduction in DW is more or less the maximum recommended. If you buy a couple sample turbo-wipps, you can experiment with those and see what the results are. You can always use the new wipps you already replaced on another instrument.

And there is Scott Jones' touchweight spring adjustment thing, I forget the name at the moment. I don't have experience with it, but a couple people have sworn by it.

-------------------------------------------
Fred Sturm
University of New Mexico
fssturm@unm.edu
http://fredsturm.net
"The true sign of intelligence is not knowledge, but imagination." - Einstein
-------------------------------------------






Original Message:
Sent: 07-02-2012 17:01
From: James Busby
Subject: Capstan Location (and Possible Re-Location)

Hi Paul,

One good thing about CAUT work is that we get to see the same pianos over and over, tweak things, and even experiment a bit. I've learned a lot from other people, classes and seminars, as well as from the CAUT list, but I'd have to say that trial and error has to be one of my top "teachers".

It's a simple matter to take out a few sample keys (2 or 3 maybe) and move the capstans, replace the stack and remeasure your action ratio. There's a lot more to it than this, of course, because you have to regulate the keys, etc. but it's an easy way to "get your feet wet". You can easily put things back the way they were, and you're only out a few minutes of your time. This has been invaluable to me; rather than obsess over it, ask everyone I know, (which is not a bad thing, but does take time) and read everything I can about it, I sometimes just do it. In ten minutes or so you may have your answer. (or 10,000 ways NOT to do it! - Edison...:-)

Regards,
Jim

-------------------------------------------
James Busby
Mt Pleasant UT
801-422-3400
-------------------------------------------






I am taking some time this summer to better study our 1970 Steinway D, which
no one, including myself, is entirely happy with in term of action or tone.
The touchweight is heavy (53-60g) and sluggish (6 leads in #1 key). But
what I've also discovered is that the capstans are significantly distal
(maybe 2-4mm) of the center of the wippen heel. I never noticed this
before, even when replacing reps in a big rush about 2 years ago. Anyway, I
pulled out the original repetitions and they're exactly the same as the
Steinway replacements in terms of wippen heel location (of course the jack
center is moved back a little on the new ones to accommodate the 17mm
knuckle location). New Steinway-hung hammers about 3 years ago.

Anyway, when the capstans meet the wippen heel, the back edge of the capstan
is aligned with the back edge of the heel felt, not at all at the center
"hump" with reinforced felt. I'm thinking this piano was manufactured this
way in 1970, had an improperly-located capstan line, and this might explain
why no one ever liked it much, from what I hear. I'm considering moving the
capstans forward to meet the center of the heels. Action ratio using Dale
Erwin's 6mm gauge is about 5.8. Is there anything further I should
consider? I mean, Steinway capstans should interface with the middle of the
heel, correct? No ifs, ands, or buts?

Thanks in advance for all help. I am at the front edge of my knowledge and
shop skills when considering moving capstans and changing something this
fundamental on a piano like a Steinway, but am thinking I'm on the right
track here.
--
Paul Milesi

Not quite enough info but it's likely that the capstan not located well and the key ratio is too high resulting not only in a misalignment of the capstan heel center (which is not that critical) but poor leverage (which is). A 2 mm move of the capstan will result in approximately .4 change in the action ratio which would move it down to about 5.4 (if your measurement is correct). That will yield a better balance weight/front weight ratio. Six leads at #1 in the bass, btw, isn't necessarily a disaster. It depends on where they are located, what the front weight is and what the overall strike weight curve looks like. Balance weight readings would tell you much more about the friction which can also be an issue. However, 5.8 ratio with 1970's D weight hammers is not a good match as those strike weights tend to be high. You can remove the capstan on a few keys (make sure you check the ratio at either end of the key board as the capstan line can be off) and simply make a capstan "boat" that doesn't require plugging and redrilling to test. Just cut off a capstan and screw it into a small piece of wood that you can move around under the wippen heal to your desired position. Put some double stick tape on the bottom to hold it in place and see how far you need to move it to get the weight and ratio you want while checking the regulation as well. I don't like to go lower than 5.4 and 5.5 is my preferred target. It's typical for these early accelerated action pianos to have high key ratios and poor leverage, btw. I have often had to relocate the capstan to the forward part of the wippen heel sometimes necessitating covering the entire bottom of the heel with a new strip of felt in order to keep the capstan from knocking against the wooden front of the cushion. That the capstan is not centered on the heel itself is not a problem. It's best to calculated this all out before you make a capstan move but you can make a determination by sampling. You'll want to examine the strike weights in the neighborhood to be sure that the sample you choose is representative and follow up by going through and establishing some type of strike weight curve. Likely you will be able to both lower the balance weight and remove some lead from the keys. David Love www.davidlovepianos.com
Original Message----- From: Paul Milesi [mailto:noreply@egroups.ptg.org] Sent: Monday, July 02, 2012 12:35 PM To: David Love Subject: [PTG CAUT]: Capstan Location (and Possible Re-Location) I am taking some time this summer to better study our 1970 Steinway D, which no one, including myself, is entirely happy with in term of action or tone. The touchweight is heavy (53-60g) and sluggish (6 leads in #1 key). But what I've also discovered is that the capstans are significantly distal (maybe 2-4mm) of the center of the wippen heel. I never noticed this before, even when replacing reps in a big rush about 2 years ago. Anyway, I pulled out the original repetitions and they're exactly the same as the Steinway replacements in terms of wippen heel location (of course the jack center is moved back a little on the new ones to accommodate the 17mm knuckle location). New Steinway-hung hammers about 3 years ago. Anyway, when the capstans meet the wippen heel, the back edge of the capstan is aligned with the back edge of the heel felt, not at all at the center "hump" with reinforced felt. I'm thinking this piano was manufactured this way in 1970, had an improperly-located capstan line, and this might explain why no one ever liked it much, from what I hear. I'm considering moving the capstans forward to meet the center of the heels. Action ratio using Dale Erwin's 6mm gauge is about 5.8. Is there anything further I should consider? I mean, Steinway capstans should interface with the middle of the heel, correct? No ifs, ands, or buts? Thanks in advance for all help. I am at the front edge of my knowledge and shop skills when considering moving capstans and changing something this fundamental on a piano like a Steinway, but am thinking I'm on the right track here. -- Paul Milesi Staff Piano Technician Howard University Department of Music Washington, DC (202) 806-4565 University Shop/Office (202) 246-3136 Cell/Text paul.milesi@howard.edu

One way to determine if the capstan can or needs to move is to look at the excursion of the jack.

With your blow distance and key dip set, does the jack bury into the rep lever stop felt? If so, then yes; you need to improve the ratio. If the jack remains close to the knuckle at full dip then other action parameters will have to be altered in order to relocate the capstan, such as blow distance and dip.

A place to start is to mark the point of the Magic Line on the wip cushion, draw a line parallel to the rep lever support post thru that point onto the key stick (if it's a straight heel). On an angled heel, extend the line so that it is perpendicular to the heel. This will give you both location and angle.  This also places the capstan at 90 degrees to the heel at half-blow, you could alter the capstan angle so that the 90 degree angle occurs at Let Off (least friction). But sometimes you need the rear portion of the capstan to engage a more distal portion of the heel to increase the ratio to achieve jack clearance with the capstan set at h/b or even simply 90 degrees to the key stick.

Look at it this way, the more forwards you locate the capstan; the less distance the jack travels from the knuckle.

Another consideration, could the top action be relocated more distal? Are the bass hammers askew of the rest felts? Is there a wide gap between the key fronts and key slip? I relocate the top action more than capstans.
 
-------------------------------------------
Regards,

Jon Page

Another consideration is action spread. A few years ago, Rick Baldassin said that 112.75 mm (4.439" as opposed to 4.375") was an appropriate spread in some instances. That may help with regulation to align the knuckle core with the jack center and locate the cushion move central over the capstan. You can increase the spread by inserting a strip of sandpaper between the rail and flange above the screw, this tips the flange. No need to remove them all, just a few on the ends and a few in-between and just loosen the rest.

Then there's always relocating the heel...

Regards,

Jon Page

Hammer Center Height and Wippen Center Height are important.
This info is a Newton Hunt oldie but goodie:

From the book, "Steinway Regulation"  by F. R. Dietz:

                                                    Model S-B         C-D

Point of hammer center                 4.6 cm          4.9 cm

from bottom of string

Point of rep center                       11.0 cm        11.3 cm

blow                                              47 mm         47 mm

dip                                                9.5 mm        10 mm

underside of keytop                      63 mm         65 mm

from keybed

As you see, the difference between HCH & WCH is 6.4 cm which may be the reason for the rear shim.

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

Jon Page

This is continuation/follow-up to my original thread started back in early July (quoted below).  Due to a departmental shake-up, my work on this piano had to be postponed, and I'm just getting back to it.  So I am still working to improve this instrument, without funds to properly rebuild or move it to a shop.

The piano is Steinway D #420394 (1970).  New Steinway hammers, shanks, flanges, repetitions as described below.  The action is what I might call sluggish/heavy.  See description below.

I am trying to figure out what other techs have done to this piano in the past, and why.  The capstans are at the extreme distall side of the wippen heels.  See attached photos.  Now I notice that the rear legs of the action stack have 1/8" shims.  Might this size shim cause the misalignment of capstan and heel?  Is this shimming something that is ever done in the factory, or is this an after-market modification? What is the reason for shimming up the stack like this?

I believe it was David Love who had asked for more info when the thread was first started (under exactly same subject).  Here is more:

Action spread = 112mm at bass end, 112.5 at treble end.
Action ratio measured using Dale Erwin's 6mm displacement gauge = 5.8.
Key height set using Steinway crowned key leveling stick = 2-5/8" to underside of keytops at middle of keyboard.

What's strange to me is that the down weight is 53g or less in the bass and midrange.  Starting in the 4th hammer section, though, the down weight increases through about the top of the 6th octave, then drops down to about 53g again for 7th octave.  Why are the 5th & 6th octaves showing this characteristic?  Are newer Steinway hammers (these are about 3-1/2 years old now) heavier in those octaves than older hammers?

Should I remove the stack shims?  How would I determine this?  Do you think changing key leading would be the way to go?  Should I try that and leave the capstan/wippen heel alignment alone, since it's basically working in the lower end of the piano?  What is going on here?! Was I too naive to think that I might be able to install new Steinway hammers on this piano without re-leading the keys?

Thanks for all your previous input, and for any addition information that might be forthcoming!

Photos attached.
-------------------------------------------
Paul Milesi
Washington DC
202-667-3136

-------------------------------------------






Original Message:
Sent: 07-02-2012 15:29
From: Paul Milesi
Subject: Capstan Location (and Possible Re-Location)

I am taking some time this summer to better study our 1970 Steinway D, which
no one, including myself, is entirely happy with in term of action or tone.
The touchweight is heavy (53-60g) and sluggish (6 leads in #1 key). But
what I've also discovered is that the capstans are significantly distal
(maybe 2-4mm) of the center of the wippen heel. I never noticed this
before, even when replacing reps in a big rush about 2 years ago. Anyway, I
pulled out the original repetitions and they're exactly the same as the
Steinway replacements in terms of wippen heel location (of course the jack
center is moved back a little on the new ones to accommodate the 17mm
knuckle location). New Steinway-hung hammers about 3 years ago.

Anyway, when the capstans meet the wippen heel, the back edge of the capstan
is aligned with the back edge of the heel felt, not at all at the center
"hump" with reinforced felt. I'm thinking this piano was manufactured this
way in 1970, had an improperly-located capstan line, and this might explain
why no one ever liked it much, from what I hear. I'm considering moving the
capstans forward to meet the center of the heels. Action ratio using Dale
Erwin's 6mm gauge is about 5.8. Is there anything further I should
consider? I mean, Steinway capstans should interface with the middle of the
heel, correct? No ifs, ands, or buts?

Thanks in advance for all help. I am at the front edge of my knowledge and
shop skills when considering moving capstans and changing something this
fundamental on a piano like a Steinway, but am thinking I'm on the right
track here.
--
Paul Milesi
Staff Piano Technician
Howard University Department of Music
Washington, DC
(202) 806-4565 University Shop/Office
(202) 246-3136 Cell/Text
paul.milesi@howard.edu

Wow. A number of issues here. You'll have to decide how far you want to get into optimizing. The shims under the stack feet are likely there because the string plane is high. Measure string heights and compare with action center elevations and bore distances. Don't be surprised if the bore distance tapers a bit at each end--it's likely to fit the string heights better. Raising the back feet is not an uncommon procedure, as I understand it, in The Basement. My experience with it is that it increases the feel of resistance at the beginning of the key stroke. So I try to avoid raising just the back. You can get away with 1/16" with little impact. But by 1/8" it is noticeable. The solution is either custom boring of the hammers, or raising both front and back. Where you run into trouble is with clearance under the pinblock. Look carefully at the drop screws as you pull the action! Some of us have been known to plane the underside of the block to allow raising the stack. A power planer is more than helpful here. The capstan location on the wippen heels, in the bass, is unfortunate. My experience so far in that part is that having the capstan contact the back side of the bump exaggerates the resistance, particularly at the start of the keystroke. So that's two counts against the feel of the action. Having it on the front side of the bump makes the action feel a bit inefficient--sort of weak, as it slides a bit on the cloth. So, there is significant leeway in the exact contact point, making it possible to adjust action leverage without moving heels. But the optimum is definitely having it centered or close to it. A long way of saying that you would very likely get good results by moving the capstan line. It would improve the initial feel of the keystroke, and would most likely allow for fewer leads/better inertia. If you want to do that, make sure you have good instructions. The only way that I know of to avoid changing key leading with new hammers is to adjust hammer weight (more correctly Strike Weight) to a previous design standard. This is one of the great benefits to Precision Touch Design, particularly for pianos that will be getting multiple hammer sets over the years. Without careful attention to Strike Weights, one should count on adjusting the key leading for each new set. Now, the other way to go with this action would be to lower Strike Weights to match the action ratio, by sanding down the sides of the hammers. This requires very careful work--determining action ratio accurately seems to be one of the more challenging aspects of touch design. Of course, the ballpark here is pretty big. The nature of the game is getting close enough to optimal to have the players accept the piano. Re-reading your post reminds me that there are those who think that up weight is more important than down weight. IMHO addressing both is definitely worth the effort. Doug ------------------------------------------- Douglas Wood Seattle WA 206-935-5797 -------------------------------------------
Original Message: Sent: 12-13-2012 15:18 From: Paul Milesi Subject: Capstan Location (and Possible Re-Location) This is continuation/follow-up to my original thread started back in early July (quoted below). Due to a departmental shake-up, my work on this piano had to be postponed, and I'm just getting back to it. So I am still working to improve this instrument, without funds to properly rebuild or move it to a shop. The piano is Steinway D #420394 (1970). New Steinway hammers, shanks, flanges, repetitions as described below. The action is what I might call sluggish/heavy. See description below. I am trying to figure out what other techs have done to this piano in the past, and why. The capstans are at the extreme distall side of the wippen heels. See attached photos. Now I notice that the rear legs of the action stack have 1/8" shims. Might this size shim cause the misalignment of capstan and heel? Is this shimming something that is ever done in the factory, or is this an after-market modification? What is the reason for shimming up the stack like this? I believe it was David Love who had asked for more info when the thread was first started (under exactly same subject). Here is more: Action spread = 112mm at bass end, 112.5 at treble end. Action ratio measured using Dale Erwin's 6mm displacement gauge = 5.8. Key height set using Steinway crowned key leveling stick = 2-5/8" to underside of keytops at middle of keyboard. What's strange to me is that the down weight is 53g or less in the bass and midrange. Starting in the 4th hammer section, though, the down weight increases through about the top of the 6th octave, then drops down to about 53g again for 7th octave. Why are the 5th & 6th octaves showing this characteristic? Are newer Steinway hammers (these are about 3-1/2 years old now) heavier in those octaves than older hammers? Should I remove the stack shims? How would I determine this? Do you think changing key leading would be the way to go? Should I try that and leave the capstan/wippen heel alignment alone, since it's basically working in the lower end of the piano? What is going on here?! Was I too naive to think that I might be able to install new Steinway hammers on this piano without re-leading the keys? Thanks for all your previous input, and for any addition information that might be forthcoming! Photos attached. ------------------------------------------- Paul Milesi Washington DC 202-667-3136 -------------------------------------------
Original Message: Sent: 07-02-2012 15:29 From: Paul Milesi Subject: Capstan Location (and Possible Re-Location) I am taking some time this summer to better study our 1970 Steinway D, which no one, including myself, is entirely happy with in term of action or tone. The touchweight is heavy (53-60g) and sluggish (6 leads in #1 key). But what I've also discovered is that the capstans are significantly distal (maybe 2-4mm) of the center of the wippen heel. I never noticed this before, even when replacing reps in a big rush about 2 years ago. Anyway, I pulled out the original repetitions and they're exactly the same as the Steinway replacements in terms of wippen heel location (of course the jack center is moved back a little on the new ones to accommodate the 17mm knuckle location). New Steinway-hung hammers about 3 years ago. Anyway, when the capstans meet the wippen heel, the back edge of the capstan is aligned with the back edge of the heel felt, not at all at the center "hump" with reinforced felt. I'm thinking this piano was manufactured this way in 1970, had an improperly-located capstan line, and this might explain why no one ever liked it much, from what I hear. I'm considering moving the capstans forward to meet the center of the heels. Action ratio using Dale Erwin's 6mm gauge is about 5.8. Is there anything further I should consider? I mean, Steinway capstans should interface with the middle of the heel, correct? No ifs, ands, or buts? Thanks in advance for all help. I am at the front edge of my knowledge and shop skills when considering moving capstans and changing something this fundamental on a piano like a Steinway, but am thinking I'm on the right track here. -- Paul Milesi Staff Piano Technician Howard University Department of Music Washington, DC (202) 806-4565 University Shop/Office (202) 246-3136 Cell/Text paul.milesi@howard.edu

Paul,
You might consider the Fandrich/Rhodes Weight Bench action analysis system and program.
See http://www.mypianotech.com/WB/
It creates a virtual model from the action measurements you enter, and it allows you to try changing the measurements to find an optimal solution, or the best possible solution with minimal parts investment.
It also calculates the inertial moments of the action.
This could be very useful in a university where you seek best improvements on a limited budget.
We hope to publish their debut articles soon.


-------------------------------------------
Ed Sutton
Editor
Piano Technicians Journal
ed440@me.com
704-536-7926

-------------------------------------------






Original Message:
Sent: 12-15-2012 10:18
From: Douglas Wood
Subject: Capstan Location (and Possible Re-Location)


Wow. A number of issues here. You'll have to decide how far you want to get into optimizing.

The shims under the stack feet are likely there because the string plane is high. Measure string heights and compare with action center elevations and bore distances. Don't be surprised if the bore distance tapers a bit at each end--it's likely to fit the string heights better. Raising the back feet is not an uncommon procedure, as I understand it, in The Basement. My experience with it is that it increases the feel of resistance at the beginning of the key stroke. So I try to avoid raising just the back. You can get away with 1/16" with little impact. But by 1/8" it is noticeable. The solution is either custom boring of the hammers, or raising both front and back. Where you run into trouble is with clearance under the pinblock. Look carefully at the drop screws as you pull the action! Some of us have been known to plane the underside of the block to allow raising the stack. A power planer is more than helpful here.

The capstan location on the wippen heels, in the bass, is unfortunate. My experience so far in that part is that having the capstan contact the back side of the bump exaggerates the resistance, particularly at the start of the keystroke. So that's two counts against the feel of the action. Having it on the front side of the bump makes the action feel a bit inefficient--sort of weak, as it slides a bit on the cloth. So, there is significant leeway in the exact contact point, making it possible to adjust action leverage without moving heels. But the optimum is definitely having it centered or close to it.

A long way of saying that you would very likely get good results by moving the capstan line. It would improve the initial feel of the keystroke, and would most likely allow for fewer leads/better inertia. If you want to do that, make sure you have good instructions.

The only way that I know of to avoid changing key leading with new hammers is to adjust hammer weight (more correctly Strike Weight) to a previous design standard. This is one of the great benefits to Precision Touch Design, particularly for pianos that will be getting multiple hammer sets over the years. Without careful attention to Strike Weights, one should count on adjusting the key leading for each new set.

Now, the other way to go with this action would be to lower Strike Weights to match the action ratio, by sanding down the sides of the hammers. This requires very careful work--determining action ratio accurately seems to be one of the more challenging aspects of touch design. Of course, the ballpark here is pretty big. The nature of the game is getting close enough to optimal to have the players accept the piano.

Re-reading your post reminds me that there are those who think that up weight is more important than down weight. IMHO addressing both is definitely worth the effort.

Doug
-------------------------------------------
Douglas Wood
Seattle WA
206-935-5797
-------------------------------------------

My apologies.
The information about the action analysis/inertia calculator has not yet been posted to the Fandrich/Rhodes site.
The current site only discusses the basic Workbench system.

-------------------------------------------
Ed Sutton
Editor
Piano Technicians Journal
ed440@me.com
704-536-7926

-------------------------------------------






Original Message:
Sent: 12-15-2012 12:00
From: Ed Sutton
Subject: Capstan Location (and Possible Re-Location)

Paul,
You might consider the Fandrich/Rhodes Weight Bench action analysis system and program.
See http://www.mypianotech.com/WB/
It creates a virtual model from the action measurements you enter, and it allows you to try changing the measurements to find an optimal solution, or the best possible solution with minimal parts investment.
It also calculates the inertial moments of the action.
This could be very useful in a university where you seek best improvements on a limited budget.
We hope to publish their debut articles soon.


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Ed Sutton
Editor
Piano Technicians Journal
ed440@me.com
704-536-7926

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Original Message:
Sent: 12-15-2012 10:18
From: Douglas Wood
Subject: Capstan Location (and Possible Re-Location)


Wow. A number of issues here. You'll have to decide how far you want to get into optimizing.

The shims under the stack feet are likely there because the string plane is high. Measure string heights and compare with action center elevations and bore distances. Don't be surprised if the bore distance tapers a bit at each end--it's likely to fit the string heights better. Raising the back feet is not an uncommon procedure, as I understand it, in The Basement. My experience with it is that it increases the feel of resistance at the beginning of the key stroke. So I try to avoid raising just the back. You can get away with 1/16" with little impact. But by 1/8" it is noticeable. The solution is either custom boring of the hammers, or raising both front and back. Where you run into trouble is with clearance under the pinblock. Look carefully at the drop screws as you pull the action! Some of us have been known to plane the underside of the block to allow raising the stack. A power planer is more than helpful here.

The capstan location on the wippen heels, in the bass, is unfortunate. My experience so far in that part is that having the capstan contact the back side of the bump exaggerates the resistance, particularly at the start of the keystroke. So that's two counts against the feel of the action. Having it on the front side of the bump makes the action feel a bit inefficient--sort of weak, as it slides a bit on the cloth. So, there is significant leeway in the exact contact point, making it possible to adjust action leverage without moving heels. But the optimum is definitely having it centered or close to it.

A long way of saying that you would very likely get good results by moving the capstan line. It would improve the initial feel of the keystroke, and would most likely allow for fewer leads/better inertia. If you want to do that, make sure you have good instructions.

The only way that I know of to avoid changing key leading with new hammers is to adjust hammer weight (more correctly Strike Weight) to a previous design standard. This is one of the great benefits to Precision Touch Design, particularly for pianos that will be getting multiple hammer sets over the years. Without careful attention to Strike Weights, one should count on adjusting the key leading for each new set.

Now, the other way to go with this action would be to lower Strike Weights to match the action ratio, by sanding down the sides of the hammers. This requires very careful work--determining action ratio accurately seems to be one of the more challenging aspects of touch design. Of course, the ballpark here is pretty big. The nature of the game is getting close enough to optimal to have the players accept the piano.

Re-reading your post reminds me that there are those who think that up weight is more important than down weight. IMHO addressing both is definitely worth the effort.

Doug
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Douglas Wood
Seattle WA
206-935-5797
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