>>Alternately, one could simply do a measurement to see how far off we are. Fix the flange, let hammer fall upside down and put a gram scale under the hammer so the line from the pivot to the strike point is parallel to the scale. (You'd have to pin it for very low friction beforehand) Say it weighs 12 grams and the distance from the pivot to the strike point is 150 mm (I am making this up for ease of calculation). Now weigh the shank and hammer assy by itself: no flange. Say it weighs 15 grams. If I'm not mistaken, the equation looks like this: CP x 15 = 150 x 12 CP =120 mm After sleeping on this all night, I am quite sure my equation is wrong. What I have derived is the center of gravity. The distance to the center of percussion is affected by the square of the distance to each rotating mass element. That is why the mass near the pivot is way more negligible than the mass at the end (i.e., the hammer). I still haven't figured it out yet. It has been too long. Dean Dean May cell 812.239.3359 PianoRebuilders.com 812.235.5272 Terre Haute IN 47802
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