[pianotech] capstain/wippen angle, was: key position at rest

pianoguru at cox.net pianoguru at cox.net
Sun Mar 15 19:05:49 PDT 2009


> Ron Nossaman wrote:
> > I don't know for sure, but I think so, with the right capstan angle 
> > and profiles. The contact points would change, sure, but I think 
> > nearly all, if not all sliding could be eliminated. That's if you 
> > didn't go above the magic line.

If the radius of the capstan and the radius of the curve of the wippen heal are such that the capstan must travel the same distance along the curve of the wippen, as the wippen must travel along the curve of the capstan, there is no sliding friction.   The two surfaces roll together synergistically.  There is still a certain amount of friction, but not so much as with sliding contact conditions.  Whether it be above or below the magic line is irrelevant.

Frank Emerson



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