----- Original Message ----- From: "Phillip Ford" <fordpiano@earthlink.net> To: <pianotech@ptg.org> Sent: September 25, 2003 9:42 AM Subject: Re: Action compliance (was Re: Heavy Hammers) > > Is the erratic hammer motion all from shank flexing? Or is some of it > coming from center pin bending or bushing compliance? I've often wondered > how we ended up with such tiny center pins. Larger pins and bushings would > seem to have less compliance. > > Phil Ford I don't know. I expect it's a combination of factors. The bushing on one side slightly more compliant than the other. The jack not seated quite square to the knuckle. The knuckle slightly skewed. A bit of twisted wood grain in the hammershank. The hammer's center of gravity slightly off center (a common thing with the hammers bored at an angle, I should think). I expect the list is nearly endless. I make my comments about the cross-section of the hammershank only because so many seem interested in using relatively massive hammers in an effort to gain more power. Until the hammershank flex problem is dealt with this won't really do much good beyond messing up the overall feel of the action. At least it won't achieve the desired results. Del
This PTG archive page provided courtesy of Moy Piano Service, LLC