Here is what I wrote about that back in June of 2020:
When replacing knuckles, investigate if the knuckle covering has a nap. (from a dictionary definition: "the raised hairs, threads, or similar small projections on the surface of fabric or suede (used especially with reference to the direction in which they naturally lie"). Your supplier should be able to tell you that information. When we replaced knuckles, they were genuine buckskin .I'm not sure what material is used now or if it has two "feels" depending on the direction. Back then, the replacement knuckles came with a pencil mark on the buckskin on one side near the spline and the idea was to make sure all knuckles went in with the nap running the same direction by paying attention to the pencil marks.
Our friend who works at Renner would not only feel with a finger which way the nap ran, but tested it on his lip which is more sensitive. My preference is to have the jack initially work "against the grain" which gives a nice "crunch" to the key stroke. Then the smoother direction gets the jack back under the knuckle, ready for repetition, faster. But I have heard others prefer the opposite direction I guess for faster action speed on the key stroke. Just another thing to consider for this project.
Joel
and
Personally, I feel the after touch as a "crunch" and try to make that feel as even as possible. Performing artists have, in my experience, appreciated that feel and the evenness. So my reason for going against the grain on the keystroke is that it fits right in with the "crunch" feel of the after touch, especially considering that the escaping jack is a major part of after touch. Further, it is not so much that the player feels the jack slipping back under the jack as they want it back as quickly as possible for the next key stroke. Alicia de la Rocha was happy when she could repeat as fast as she wanted without letting the key return all the way up. Having the knuckle nap smooth on the jack return contributed immensely to accomplishing that, as well as having the knuckles lubricated with talc or teflon powder or whatever you prefer. Most artists with whom I have worked also want that quick repetition. In my opinion, having the jack top fight the rough nap during its return would slow these top performers down.
Now some might say "The rep lever raises the knuckle up so the jack top is not contacting the knuckle on its return." To which I would say "Not as fast as the top performers play; it seems these players need the jack back in position and ready to work before the wippen spring can think about raising up the rep lever." And keep in mind, these folks have pretty strong fingers and control so a little bit of resistance on the key stroke not only presents no problem for them but most likely adds to their control. That's my read of the situation. Also, our general philosophy is to give the home user the same top-performing action as the one set up on stages. I can't tell you the number of times a customer at home has had their teacher or even a top-performing friend come over and try the newly rebuilt piano. So we use the best materials and procedures we can. But if casual players at home are bothered by the resistance, I can see why a technician would want the nap going the other way. Anyone else prefer one way or the other and what are your reasons?
Joel
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Joel Rappaport
Round Rock TX
(512) 255-0440
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Original Message:
Sent: 04-25-2023 21:49
From: James Kelly
Subject: Abel Knuckles
Can someone tell me where the score mark on Abel knuckles should face ? should the line be toward the hammer felt or facing the stack & keyboard ? I am replacing the chewed up/shredded knuckles on a Samick
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James Kelly
Owner- Fur Elise Piano Service
Pawleys Island SC
(843) 325-4357
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