>why not approach the analysis more simply. In addition to the use of >touch weights, look at the key travel the action needs in order to produce >enough aftertouch (not too much or too little) with a standard hammer blow. If >the key travel "mandated" by the action is less than 3/8", you have a low >leverage action that will be inertia laden (hard to accelerate). The farther >away from 3/8" (less than 3/8), the more the inertia. If you want to use a >heavy >hammer in this action, you will have to change the leverage or possibly have a >piano that could be far too heavy to play. > >Conversely, if the action "mandates" key travel greater than 3/8", you have a >high leverage action that will be less inertia laden (easy to accelerate). Use >heavy hammer if you want. >This is an over-simplification, but it sure could help technicians get an idea >about what's going on in an action. Sounds good Ken, but I can see a problem with interpretation of how dip and aftertouch is measured. The squishiness of the felt and how it is compressed is a big factor here and interpretation of "dip". It's certainly easy to use a vernier caliper to depress a key and accurately measure how far it moves, but an accurate definition of were to stop is needed. How about, just for testing puposes, checking the dip with a solid front rail punching and measuring the key travel to where it stops? That way the point of bottoming out is for certain. David Stanwood David C. Stanwood-Stanwood@tiac.net West Tisbury, Massachusetts USA On the Island of Martha's Vineyard http://www.tiac.net/users/stanwood/st&co.htm "The art in hammer making has ever been to obtain a solid, firm foundation, graduating in softness and elasticity toward the top surface, which latter has to be silky and elastic in order to produce a mild, soft tone for pianissimo playing, but with sufficient resistace back of it to permit the hard blow of fortissimo playing." - Alfred Dolge 1911
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