Jim...and others may correct me where I am wrong here.... but I THINK that Ron was getting at the more general question of what shape of a shank yields the most stiffness for same << diameters >> I dont really see the point in using inertia in this regard myself... I fail to see the connection between a things moment of inertia, and its stiffness... Besides there are formulas to do show stiffness for different shapes rather directly unless I'm mistaken. RicB James Ellis wrote: > > Ron, > > We are not talking about center-loaded structural beans, static-loaded > floors, how much the floor jiggles with how much static loading, etc. We > are talking about hammer heads out on the ends of shanks. In this case, > the moment of inertia of the shank itself is almost negligible. The moment > of inertia is all concentrated out at the hammer head, and we don't want > the hammer head to wiggle and wobble as it hits the string. But at the > same time, we don't want a shank that has so much mass that it's vibrating > center causes the hammer to wiggle. We are playing stiffness of the shank > against it's own mass against the mass of the hammer head that is rotating > end-over-end because it is moving in an arc. I hope to prove my point with > some measurements. However, if my measurements don't prove my point, I > will take a back seat and be quiet. It will be a few days before I can get > time to do this, but I think it will be worth it. Thanks, Ron, for your > comments. > > Sincerely, Jim Ellis > > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html http://www.hf.uib.no/grieg/personer/cv_RB.html
This PTG archive page provided courtesy of Moy Piano Service, LLC