Eliot Lee wrote: > > Hi all, > > Usually I file grooved hammers, but I don't really know why, just > that everyone says so. Doesn't it effect the hammer flange pins in some > way? Can deep grooves come out with steam or fabric softener? > > Also at Don Mannino's class at the California State convention he > mentioned doing a complete repinning of hammer flanges. What should the > gram resistant weight be? I bought a reversable balance scale and don't > know what constitutes the optimum weight for hammer flanges, or wippen > flanges. I know one way of testing is to let the hammer free fall 4-6 > times, but would like to use the guage since i have it. What amount of > variance in gram weight resistance is acceptable? ------------------------------------------------------------------------------- Oooooh boy, major 3 week+ thread about to start here.... Eliot, Hammers are supposed to be round with a slightly pointed peak toward the strings. While the grooves are created via some compaction the primary cause is because material has actually become worn away. This can be observed by the powdered felt dust that usually settles on the back half of the action, bridge tops, etc. (refering to an upright). Hammers need to be smooth and peak/rounded because this shape lends superior to efficiency and tonal quality. The complete partial series of the strings, particularly the higher partials, are much more responsive with a blow on a pre-determined and ideally focused location of the string. This is called the strike point. For lack of a better example, consider knocking on a window pane. Which is more effective, using your flattend out hand or using your knuckles in a concentrated effort? There are far more details but I'll leave it at that. I'm sure many others on this list will add. Using steam or fabric softener is a whole different ball game and relates more toward voicing then grooves. This is not a solution, reshaping comes first and then voicing. As far as flange pins go I believe that flat hammers can be more stressfull. Relaying my "personal theory", this is because of added vibration transmitted down the hammer shank in addition to harder blows produced by the pianist in failed efforts to improve tonal quality. Just how much this contributes to wear I couldn't say but the primary stresses would logically be on the bushings. I'm certain many others can elaborate on this. As far as gram resistance for hammer flanges, I simply use the ol' standard swing test. It's quick, easy, and pretty accurate. I have a gram gauge someone gave me but never really found the sense in using it. Ok, someone else's turn.... Rob Goodale, RPT, Generally swell guy.
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