J Patrick Draine wrote: > > On Jul 12, 2005, at 2:48 AM, Geoff Sykes wrote: > >> >> Loose hammer flanges sounds like a real likely culprit. How many >> times have we checked the pinning on a brand-new hammer flange only >> to see eight or ten swings? Since this is dealer prep I think I was >> actually avoiding that as a possibility. > > > Good god, Geoff! This is Yamaha that we're talking about -- not a > company that wants products out in the world that are "semi > acceptable!" Go back, check the pinning friction, and then give Yamaha > tech support a phone call (better yet, call them first!). I'm sure > they will help you figure this one out (and make sure you're paid for > your efforts). Just a guess -- if the center pin/flange friction is > within specs, are the return springs too strong? > > Patrick Draine > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives > > I used to work for a Yamaha dealer in the 80's and called them repeatedly about this problem and they refused to admit it was a common thing in Yamaha verticals. They always told me to double-check the regulation and the pinning. My thought was, "These are brand new pianos by a supposedly reputable manufacturer and dozens of jacks and hammer flanges shouldn't have to be re-pinned on new instruments!" Here it is 20 years later and techs are still encountering the same problem. They've never addressed it. I think part of it may have to do with the curve of the butt leather compared to other hammer butts -- maybe the jacks sit too far under the butt; I don't know. And I don't have sophisticated enough equipment to experiment, such as high-speed photographic equipment to analyze the movement of the jack in relation to the butt, or machines to mill different curves on hammer butts. But you'd think a big, wealthy corporation like Yamaha could afford to re-tool their butt-shaping machine or research their action pinning torques to get rid of this ongoing botheration. --David Nereson, RPT
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