Ok Jim... I'm going to throw something out for ya's alls considerations.... I know the hammer has the most inertia swinging out there on the end of that stick. But isnt that rather reduced in how much of that inertia is felt at the key by the ratio of the action ? I would think... on the surface of things... that if the action ratio is around 5 to 1 then whatever the moment of inertia is for the top action... by the time leverage gets through doing its bit... the finger would only << feel >> 1/5th of that inertia moment. And if that is the case... then suddenly the front moment of inertia for the key becomes quite a bit more significant. comments ?? Cheers RicB James Ellis wrote: > > Ed, Don, Isaac, Richard, Vince, > > Since posting my latest memo, I have been thinking. There might be one > case where putting more leads closer to the center of the key to reduce the > "key" inertia might help a little bit. That is in the case of partial-blow > repetition, where the jack just gets back under the knuckle on fast key > release from check, and the blow is repeated before the hammer has time to > come back to rest. In this case, the hammer has not yet come into the > picture as far as return acceleration is concerned. It's still up in the air. > > Ed Sutton suggested some measurements, and I think that might be a good > idea. If the concensus of the group is for it, I can do it. I would > propose to measure the return time of the jack under the knuckel following > sudden key release, and also the acceleration of the hammer on return from > check. I would expect these two measurements to be quite different, and I > would expect the reduced key inertia to allow the jack to return under the > knuckle a little bit faster, but nothing dramatic. I would not expect much > difference in the return time of the hammer to the rest position. It might be interesting to compare this also with the case of an assist spring action that holds the whippen up. > > All of the above would need to be done from the checked position after > sudden key release. Anything else would simply be measuring hammer rebound > time. > > It will require some set-up time to do the test, but I will do it if there > is much interest. If not, I won't. What's your pleasure? Would you like > me to set up the test and do the measurements? Sounds interesting.. I'd like to see the results of this for sure. > > Jim Ellis > > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives Cheers RicB
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