Jim Parker wrote: > I'm not sure I would ever straighten a sloping capstan. Steinway did that > for a reason. The sloping capstan matched with a sloping whippen heel > yields zero friction between the two. That is because they roll on each > other due to the matching involute(?) curves rather than the capstan > sliding against the whippen heel as it rises. This was explicated > beautifully by Chris Robinson many years ago at a convention class I > attended. At the time replacement whippens from Steinway with the sloped > heel were unavailable and Chris was cutting his heels to get it. Later > Steinway again began offering the original type heels for rebuilds on older > instruments I believe. > - I've been doing an awful lot of looking at friction moments for a while now... and frankly... I dont see the capstan / heel relationship as a major contributor at all... even with the so called slidding capstan syndrom. It only becomes measureable when the combine weight and leverage of the hammer, hammershank, and whippen is quite heavy, and even then you have much bigger worries at the knuckle to concern youself with. That being said... I like (intuitively at least) the idea of creating a sort of pivot like action between the capstan and the heel. I just dont think its at all a critical issue. Some folks go so far as to tilting the capstan 15 degrees bacwards just to be able to make a little extra move forwards in capstan replacement... and I've yet to record hearing any major problems resulting from that. RicB -- 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
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