Virtual Capstan

[Isaac OLEG]

Ron,

I agree, it works because it change the leverage, having a magnet in
the whippen would not change it, and then we should be in the 10lbs
bag comparison.

It is lessening the friction a lot probably, that may change under
real play modes, while I don't understand how the magnet force act
verse the inertial mass of the parts (what are the elements involved
?)

A couple magnets in the whippen rail and whippen lever should more
work as assist springs (and with the same pitfall in regard of the
help given only at the beginning of the stroke).

I bet that only once installed in a real action one can evaluate what
it really gives, but if it help to break the initial inertia that is
yet great, as this is what pianist tend to complain the most.

The effort is given in the same direction of the whippen lever spring
also, so is the lesser friction at the heel  meaning more friction at
the roller/lever interface, or does it stay the same under the same
global force applied ?

I wonder if a magnet is not exactly acting in the most optimum way
against inertia lessening it far better than a spring because of its
permanence.

how is the friction acting under load ? if the friction is less to
begin with it may well stay at lower level for all the stroke.




Isaac OLEG

Entretien et reparation de pianos.

PianoTech
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> -----Message d'origine-----
> De : pianotech-bounces@ptg.org
> [mailto:pianotech-bounces@ptg.org]De la
> part de Ron Nossaman
> Envoye : dimanche 22 juin 2003 19:12
> A : Pianotech
> Objet : Re: Virtual Capstan
>
>
>
> >Ok, so putting the magnet(s) behind the capstan makes the
> action heavier as
> >the key moves, in it's stroke. I can understand that.<G>
> Why not put the
> >magnet "IN" the wippen heel? It would take more work to
> install, but
> >wouldn't change the basic "ratio", (?). In this way you
> could define how
> >much the magnet(s) effect the actual "touch".
> >Best Regards,
> >Joe Garrett, RPT, (Oregon)
>
>
> If it doesn't change the ratio, it won't lessen touch
> weight. That's why.
> Putting the magnet in the heel would be no different than
> putting in a
> non-magnetic weight. The magnetic lift and mechanical
> advantage from the
> second class lever of the wippen is the only thing that
> makes this work. So
> far, it looks like I am the only one who has actually taken
> a little time
> to try and work out the leverages involved. Forget action
> terminology for a
> moment (pun intended), and go back to basic mechanics.
>
>
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