Hi Chris Grin... dont really see what you are apologizing for, but let go. Your posts have been thought provoking and well thought out seems to me. I've heard about the class you refer to and hope to run into this one on one of my infrequent visits stateside... HEY !... perhaps we can get you two to do the Nordic ? :) I still dont really see clearly how we are going to see a significant reduction in friction at the capstan/knuckle interface if all one is doing is removing a couple grams of weight there... much less if all one is doing is keeping the existing weight on the capstan but changing how much each of the two top action components individually contributes to that weight. Even up at the top where the weight on the capstan can easily get as low as 70 grams... a subtraction of a couple grams of whippen weight only reduces the total weight at the capstan by just under 3 %. And in the bass the total weight reduction would only be about 1 %. I can certainly imagine how dropping the weight at the capstan by the total amount of whippen radius weight (using assist springs) might significantly affect friction there, but then you are reducing weight at the capstan by significantly more in that case. About 25 percent in the above example... and say around 10 % in the lower bass. Still... seems to me the bulk of friction in the action is to be found elsewhere. In your looking into all this, have you and Don tried simply removing the hammer all together and attach comparable weight to the jack top to see what friction change there is in a <<with knuckle/jack friction and without>> scenario ? Cheers RicB I apologize Ric. To do this more"scientifically" you should of course remove lead from the key before/after hooking up the spring or after removing weight from the wip in order to maintain a constant BW. This is something Bob M and I discovered in our class recently in Oklahoma. We now use models to teach these principles, made by the Florida State piano technology grad program, with exchangable shanks having 15, 16 & 17 (10) mm knuckles (constant StrikeWeight), movable captstan boats, asssist springs, easily removable and replaceable leading, and we also introduce the cut punching and balance rail shimming techniques. Used to be hard to get these things across but thanks to the models we have arrived at a real method for teaching these concepts. And we are discovering additional benefits like "wow where did that additional friction reduction come from?" I agree with you, it must be a slightly higher Ratio than we would like for a happy marriage with the SW, but it appears nothing is to be done on this account. It has, however, provoked some interesting discussion. See ya on the web, Chris Solliday
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