On Dec 4, 2010, at 2:19 PM, David Stanwood wrote: > Fixating on making accurate down weight results in diminishing > returns very quickly simply because down weight is never felt by the > pianist because it never goes through let off The feeling through let off is certainly important, and it is measurable. And it is measured by many if not most German techs, from what I understand, at least as a sort of final diagnostic check. Start with whatever weight it is that gets the key to move and go to where the drop screw stops it, then add weight and see how much additional it takes to go through let off. And it is interesting to see if that total weight does, indeed, make the key go through let off from rest (ie, you can add weight when the key is supported by the drop screw, to see how much it takes from that point to go through let off, as the other possibility). It usually takes a little less from rest, I guess because of the momentum. Really pretty simple, and I think that the "through let off" measurement is more important to the touch. Note that it is dependent on friction and spring tension acting together. Knuckle condition, jack alignment, drop regulation, rep spring tension, centerpinning, all come into play. Leading keys based purely on DW is the real bugaboo, and it seems that most pianos out there were/are done that way. All very "custom" and "precise" <G>. Except that nobody (usually) has bothered to be certain, for instance, that the key bushings are all free and nothing is rubbing. Hence we find leading that is all over the place. I prefer pianos that have simply been pattern leaded. Regards, Fred Sturm fssturm at unm.edu http://www.createculture.org/profile/FredSturm
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