Ed, My hats off Jim Ellis as well for his original thought. When I came up with the Balance Weight system in 1990 I thought it was my original thought... that is to say, I came up with the concept on my own without prior knowledge of the formula. So in that sense I enjoyed the sense of original discovery. However, it was soon pointed out to me that, while I may have had a new method for balancing keys that accounts for friction, Don Gault gets credit for the original formulas for weight and friction which he published in the Journal 1969. On the line of this discussion, I remember vividly a conversation, years ago, I had with a PTG member (I remember the face but not the name) who related to me that he used to work with Keith Hardesty in LA and told me about a method that Keith used which is the same as that described by Jim. I don't want to diminish Jim's discovery... just offer what I've heard in relation to it... If anyone knows more about Keith Hardesty it would be nice to learn more about this interesting Tech... David Stanwood > Dear List- During our discussion of inertia in piano actions a >few months ago, Jim Ellis presented some of his thoughts on the problem, >including the suggestion that weighing off should be done relative to a >target balance weight. Opportunity came in the form of a small >Knabe action in which just about every design decision was wrong. To >interpret Jim's idea, I made three pairs of weights, representing >varying amounts of friction with a 37.5 gram balance weight, thus: > The goal is to produce equal speeds of and down movement for >each pair, but faster as you compare the 25/50 weights with the 22.5/52.5 > weights and then the 20/55 weights. Observation with the >weight pairs made the improvements of each change very obvious. > and second-guessing was minimal. My hat's off to >Jim for this idea. Ed Sutton
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