Peter writes:
'Additionally, it seems that all the "standard" regulation specs we are used to have a built in "safety factor" to accommodate various playing styles, various climates and seasonal change, etc. Considering the fact that the vast majority of pianos are not intended or used for concert performance, it would seem that as long as there is not some "baked in" defective setup from the factory, the standard specs should work pretty well under normal conditions'
I agree. One point worth considering is value. I cannot justify the same amount of time setting up the regulation of a wooden action if I am going for all out performance, as whatever state of pinning I regulate with is going to immediately begin changing. It will remain usable, but that one variable is going to be the weak link in the chain we call 'regulation'. Since spring strength is heavily determined by friction, and its strength determines other sensitive initial settings, (like jack position and mortise height), having it subject to variety requires I leave a wider margin for error than with the composite parts. They allow a narrower 'window' to be worth pursuing, as the results will be more durable, long-lasting, and ultimately more valuable.
regards,
Original Message:
Sent: 2/9/2026 8:01:00 PM
From: Peter Grey
Subject: RE: Jack-to-knuckle alignment question
I have used them on the last two rebuilds. I think they're great (so far), and noise has not been an issue (again so far) a year or more in.
Additionally, it seems that all the "standard" regulation specs we are used to have a built in "safety factor" to accommodate various playing styles, various climates and seasonal change, etc. Considering the fact that the vast majority of pianos are not intended or used for concert performance, it would seem that as long as there is not some "baked in" defective setup from the factory, the standard specs should work pretty well under normal conditions. What were talking about here is along the lines of "custom optimization", which certainly can improve things, but as we know...there are always ramifications. So it goes without saying that if we're going to depart from these specs, we need to be prepared for dealing with possible collateral issues.
Peter Grey Piano Doctor
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Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com
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Original Message:
Sent: 02-09-2026 11:24
From: Edward Foote
Subject: Jack-to-knuckle alignment question
The one problem I have encountered with the WNG hammer shanks is noise. The conposite material doesn't seem to dampen noise in the action parts like wood does.
Has anyone used the newer WNG knuckles with the solid core, and if so, are they quieter on release? I haven't been able to put a WNG in a recording venue because of the rattle that the microphones pick up as the keys are released.
Regards,
Original Message:
Sent: 2/9/2026 8:56:00 AM
From: Ed Sutton
Subject: RE: Jack-to-knuckle alignment question
WNG parts use pseudosuede (aka ecsaine) in place of buckskin.
Pseudosuede is manufactured to very exact standards, very even thickness and very even friction.
It is also virtually indestructable in piano actions. An engineer reported no discernable change after one million impacts.
These may be small differences compared to buckskin, but as has been said, small differences compound in the piano action.
[By the way, this is not the imitation suede (corfam) that failed miserably in Baldwin verticals.]
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Ed Sutton
ed440@me.com
(980) 254-7413
Original Message:
Sent: 02-07-2026 13:16
From: Robin Whitehouse
Subject: Jack-to-knuckle alignment question
Thanks for your added knowledge, Ed. What about posterior and anterior? That seems to work well as they refer to the structure itself, instead of requiring a reference point, and I think we're universally inclined to think of the backcheck area as behind the keys area.
I see a difference between the Cliff Gears method and the David Hughes method: Feeling for the loss of power is subjective, and the amount of effect from the twist a regulation button is often random due to the non-exactness of that interface. In David's method, there's likely some subjectivity to it, but I think the controls are at least a little tighter because it depends on an observable point of interaction.
Your point about the consistency of WNG parts I think rings true – because of that consistency, the visual and/or consistent placement of the jack will most often result is very consistent behavior. But throughout this whole discussion, I've become convinced that consistent behavior of the jack is far more impactful than consistency in positioning. (Again, in your case with WNG parts, I expect that you find consistent behavior to accompany consistent placement, therefore what I'm suggesting becomes a moot point, so I'm certainly not arguing this point to you.)
Thanks for sharing your contrary view on rep lever pinning – very helpful for considering all angles. While I should experiment more before making a full case, it's my thinking that a higher static friction of the rep lever balanced against the dynamic operation with higher spring tension, could create a different effect than simply changing placement of total equal frictions. Regarding key return-acceleration, if the rep spring tension is balanced against the hammer shank to produce the same upward behavior, shouldn't that also have the same effect against the key, regardless of rep lever pinning friction? Perhaps this all works differently for WNG parts, but according to the rep-levers I just repinned, it absolutely established the ability to regulate with simultaneous jack toe and rep lever stop points, whereas it was not possible before. Also, drop behavior is very consistent now, whereas it was not before. In fact, there's a bit more drop now than I prefer – which I will remedy by adjusting the jack to be on the posterior side of the knuckle core; which is contrary to my initial inquiries in this thread. All rep levers were at 2g friction previously, and within 6-8g now.
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Robin Whitehouse
Greenbelt, MD
D.C. Chapter 201
Original Message:
Sent: 02-06-2026 10:00
From: Edward Foote
Subject: Jack-to-knuckle alignment question
Greetings,
David's approach to setting jack position, (and, could we refer to its position as 'distal' or 'proximal' instead front of action or back?), is much like Cliff Gears proposed in the 1970's. Cliff taught that you should play the note forcefully and move the jack proximally until you felt the 'loss of power' and then turn it back just a little. I never followed that due to the lack of precision, which was, at the time, my guiding principle. I may be spoiled by the consistency of WNG parts, but I set the jack to the knuckle conventionally with the distal edge of the jack no farther than the distal edge of the core and concentrate my time on other things. Some of the Baldwins with Renner actions of the '80's seemed to actually require the jack be more distal to prevent skipping, and I have regulated actions that were dependable with the jacks well proximal of what I expected. So, as mentioned, knuckle shape, nap, and placement can require the jack to be in a variety of places.
As an aside, I saw mention of a rep lever pinned at 8 grams. This is well above what I have found comfortable, as that much resistance creates a much more noticeable bump at the onset of the escapement event. Springs do all they can do ( in accelerating the key's return) with a total 7-8 grams friction shared between the shank and the repetition pinning. With felt bushed parts, you need at least 4 grams in the hammershank to have any stability with mf and above playing, as well as tonal control at the ppp level. That leaves about 4-5 grams available for rep pinning. One can get the same spring strength any way the total friction is divided between the centers, but there will be a different response and feel between a 1 gram hammer flange with a 7 gram repetition lever vs. 4 grams in the hammer and 4 grams in the repetition lever. WNG bushings don't need but 1 gram of friction to provide more stability than a felt bushed one with 6 grams but doing so requires the repetition lever to carry the rest of the needed resistance. I repin the composite flanges to 3 grams and put the 5 grams in the rep. This gives sufficient springs without excessive bump to the escapement.
regards,
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Ed Foote RPT
Original Message:
Sent: 02-01-2026 07:42
From: David Hughes
Subject: Jack-to-knuckle alignment question
Robin,
Below is a letter to the editor of The Journal that I wrote in December 2025. I made the decision to pull it from publication - it was slated for the February 2026 edition. Perhaps you may find it of interest.
"With reference to Jason Cassel, RPT's method of regulating grand piano jack alignment in the November 2025 Journal, I believe there is a more reliable and finite method that does not rely on parallax eyeballing, a temporary jig, or depressing the repetition lever.
With the jack "ballparked" under the knuckle, perhaps a tad too far to the rear of the action, the hammer is restrained from rising while the key is forcefully pushed downward, thereby jamming the action. With repeated iterations the jack is progressively adjusted father toward the front of the action until the jack skips out from under the knuckle. This establishes the cheating threshold for that key. The jack is then set back under the knuckle just far enough that the jack will not cheat under the stiffest key actuation. This method was endorsed by Norm Neblett, RPT who Jason references in his article, and who appreciated my broadcasting of the technique in my convention classes, as I still do.
I feel this is the most certain way of dynamically establishing jack placement, as it inherently takes into consideration knuckle nap and diameter, jack top lubricity, and minor deviations in repetition lever height from note to note, proprietary to each key's mechanism, and is not an 88-key dogma of how a jack is supposed to address a knuckle. The method ensures the jack dwells under the knuckle for the shortest period of time, having to travel the least required distance both to and fro to do its job, thus reducing friction, benefitting repetition, and resulting in a buttery key feel. Further, it sports the fringe benefits of expedience in regulation and elimination of setup and tedium.
Indeed, this method is akin to Jason's excellent advice on the setting let-off later in the same article."
David G. Hughes, RPT
Baltimore Chapter
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David Hughes RPT
Vintage Case Parts
Glyndon MD
(443) 522-2201
Original Message:
Sent: 01-29-2026 13:49
From: Robin Whitehouse
Subject: Jack-to-knuckle alignment question
Can anyone give an explanation for why the jack and knuckle should be aligned at the rear edge, and not further under the jack?
If going shallower under the knuckle, it will of course cheat out, trip early, lose power, etc. But I don't recall ever hearing a reason that the jack couldn't be positioned deeper under the knuckle core – assuming that other operations are not impeded when doing so.
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Robin Whitehouse
Greenbelt, MD
D.C. Chapter 201
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