----- Original Message ----- From: Don Mannino To: 'Pianotech List' Sent: Saturday, August 11, 2007 9:21 PM Subject: RE: action center question Brittney, Here are my usual guidelines, with notes. Gram measurement is made with a spring gauge at the screw hole, except where noted. hammer flange centers Depends on felt quality and firmness. My usual range would be 2 - 6 grams, depending on humidity and bushing quality. 2g during dry conditions is OK with good bushings, but will give poor tone with spongy bushings. If it's raining and the bushings are not especially firm feeling, pinning at 6 grams might be good. Evenness from note to note is most important in this center. whippen flange centers 4 - 6 grams balancier center 4 - 5 grams measured at the drop screw pad (with spring detached, of course). This is a very tight feeling bushing when you are testing with the center pin. Jack should be pinned so that it falls slowly of it's own weight when the wippen is held with the jack tender pointing up. This give a correct amount of friction to match the weight of the upper part of the jack, which helps control unwanted jack bounces during fast play. Don Mannino -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20070929/b9ac6ab1/attachment.html
This PTG archive page provided courtesy of Moy Piano Service, LLC