This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Hi Don, Yes, I agree with you, when one is needs to characterize the system = accurately and not merely conceptualize it. You're correct that the = distribution of masses in the system is far from ideal. =20 That aside, you raise an interesting point... <<Major Reason: The shank is also rigid, so the mass of the hammer head = wouldn't even act from its center of gravity even if the shank had zero = mass. The center of percussion of the whole hammer (which is nowhere = close to the cg of the head or the whole hammer) would determine its = behaviour and a non-trivial (though easily calculable) part of the = impact would be absorbed by the pivot itself as a result. >> YES! Which raises a point I've scratched my head about. Why is the = hammer aligned the way it is on the shank? It makes no sense to me. Probably any baseball player would know that it's not smart to hit the = ball with the very tip of the bat. It makes for a nasty shock to the = hands (and to the extent that the hands are not rigid in space, it takes = away from the power transferred to the ball). Why do they do this with = piano hammers? More to the point, is this not considered an = unneccessary demand to put on the hammer flanges and bushings? Perhaps = it's also a drain on efficiency? Wouldn't it make sense to have some = sort of asymmetrical molding whose center of mass is on the far side of = the action center, so as to put the center of mass of the hammer = assembly closer to the line of strike? Also, wouldn't it at least make sense to angle the head of the hammer = inwards slightly, so that the radius to the head's center of mass is = perpendicular to the strike axis of the head? It seems to me that this = would help to control wobble in the hammer I'm not sure I agree about part of the impact being "absorbed" by the = pivot. Sure, there would be force against the pivot, but for impact to = be absorbed, the pivot would need to be compliant and inelastic. I = realize that's true to an extent, as no system is ideal. However, do = you think this would be a substantial drain of energy? It seems to me = that the hammer felt and the strings are far more compliant and are = closer to the center of mass, such that almost all of the energy would = be dissipated there (rather than at the comparatively rigid center). = Have you ever measured this? Just curious on your take. I can't do much more than scratch my head = about this one. If the hammer were perfectly rigid and the center = bullet proof and noncompliant, there'd be nothing to worry about. But = considering that it does the hokey pokey and shimmies all about... = Well, I don't know. Peace, Sarah PS I do appreciate that you're not being a "wise guy." I enjoy = discussing this stuff too. It's been forever since I took college = physics, and I have to exercise the gray matter every now and then to = retain some fraction of what I learned. Of course I studied physics = before Isaac Newton came along... so that changed everything!! ;-) ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/d3/0a/97/de/attachment.htm ---------------------- multipart/alternative attachment--
This PTG archive page provided courtesy of Moy Piano Service, LLC