[pianotech] key position at rest

[Ryan Sowers]

I went to the class on Steinway patents at the Annual Convention in Anaheim
last summer and they discussed the angled capstan. The reason that was given
for NOT installing capstans at an angle was to save wear on the wippen
center. The claim was that a straight capstan caused less wear and tear on
the wippen flange bushing. I may have not understood this correctly, but I
believe that was the reason given.

On Sat, Mar 14, 2009 at 4:33 PM, Richard Brekne <ricb at pianostemmer.no>wrote:

> Hi Paul
>
> David has it right. The idea of leaning the capstan forward instead of
> backwards has to do with the friction between the whippen heel and the
> capstan. You have two parts both moving in arcs, and at half way through the
> key stroke, these arcs should be touch.  The idea is that this condition
> yields the least friction between the two parts. So in order for this to
> happen, the <<point>> of the capstan and the <<point>> of the whippen heel
> should be exactly parallel and on the same line at half blow. It makes good
> sense but as to whether or not one can measure a difference ... well I
> haven't actually measured such things myself... so I wont presume to answer
> that.
>
> Why they angled them backwards I'm still unsure of.  I've thought at times
> they must have thought they were getting more leverage out of the lever.
>  That doesn't really quite wash when it comes down to it.  You put a
> vertical force on an angled input to a lever and you get into vectors... and
> everything is moving anyways.  Like I said to begin with... I don't really
> understand what they were thinking about when they angled them backwards.
>  Still, the folks what designed things back then were not exactly idiots.
>  Might be nice to know.
>
> Cheers
> RicB
>
>
>       David:
>               Recalling would presuppose a calling! :-)
>               This bit about Ron Overs' action design is news to me. Does
> Ron       offer (is this really old news?) insight into his reasoning and
>       does he have  demonstrably measurable results? If this is an
>       archive matter, just say so, and  I'll do the work! :-)
>               Thanks,
>               Paul
>
>
>
>


-- 
Ryan Sowers, RPT
Puget Sound Chapter
Olympia, WA
www.pianova.net
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ptg.org/pipermail/pianotech_ptg.org/attachments/20090316/2e946f3e/attachment.html>