What are you replacing? If you are replacing the shanks and hammers only, you can use a shank from Abel (Wally Brooks). They make a Knabe shank with a 17 mm knuckle. If your averages are correct, a slight increase knuckle dimension will bring your R under 6 by a bit. Recalculate the strike weight range using the FW maximums as suggested by Stanwood charts. That will give you a maximum SW curve. If that doesn't fall within the range that you want a slight move of the capstan to a .52 ratio will probably bring R down enough to accommodate. At present it appears that the strike weights are not a good match for the ratio. With respect to the magic line, it will be difficult to change the knuckle line because you will be limited with knuckle size on the replacement shanks. With the capstan line, you can figure out how thick the heel cushion needs to be by building it out as you move the capstan down and setting up a line to view the results. Block the key at half blow (hammer halfway to string height) and adjust the capstan heel thickness with temporary shims, turning the capstan down until you hit the magic line. When you've done that and can demonstrate that the key will regulate properly you can consider whether or not to alter all the wippen heels. You will also want to explore how a move of the capstan will effect the magic line and consider that as an option to kill two birds with one stone--improve your leverage and get the line more in order. You may need to build the heel anyway, but better to know that in conjunction with a capstan move. You will have to do some trial and error here and set up a few sample keys to make sure everything will regulate properly. At least I would start there. David Love ----- Original Message ----- From: "Farrell" <mfarrel2@tampabay.rr.com> To: <pianotech@ptg.org> Sent: January 05, 2003 6:39 PM Subject: Touchweight Question 1902 Knabe grand. Average of 15 keys - DW = 53g, UW = 20g, F = 16.6g, KR = 0.53, WW = 16g, KC = 16.7, R = 6.0, SW = medium to medium high. Too much friction in action, OK. Everything else looks OK. BUT magic lines are all out of whack (capstan is way high, and knuckle contact is way low), and bass keys have six leads in them (YES, THAT'S RIGHT, SIX LEADS IN EACH KEY!!!!). I know something has got to change here. I'm ready to go fishin' with new parts. Any great suggestions on where to start? (Constructive, please.) Terry Farrell _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives
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