>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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