Virtual Capstan

[Richard Brekne]

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Mark Davidson wrote:

>   >Richard Brekne wrote:"Well, first and formost, what is happening is
> that Im essentially increasing leverage with respect to weight only.
> The position of this << invisible capstan >> is important. Putting the
> magnets behind the capstan would make the action heavier at the key
> front.. The force pushes up as much as it pushes down. (again your
> Newtons Third). Thats why I call it the an invisible or <<virtual
> capstan >>. Thats what it functions like (a bit springy.. but thats
> not important because we havent removed the real capstan.) It very
> well splits the leverage components (distance and weight) into two
> independantly adjustable quantities. This works by changing weight
> leverage without changingdistance leverage, to put it that way. " I
> agree that moving some of the upward force closer to the balance rail
> increases leverage.  But consider for a momentthe example of moving a
> regular capstan toward the balance rail.  Downward force required to
> move the key is decreased.Work at front of key = force * distance,
> which is less because force is less.However the wippen and hammer also
> do not move as far, so the work at the back of the key is ALSO less.
> The changes balanceout.

True.


> With your idea, however, the wippen and hammer move the SAME distance
> with or without magnets (same amount of work at back of key)but with
> different amounts of work at the front of the key.  This is actually a
> huge advantage because you do not have to re-regulatedip/blow etc.

Yes.. thats the way I see it.

Mysterious ?? not really.. Think about what would happen if you actually
had two real capstans / whippen cushions. One placed like the existing
one and one placed where this magnet << virtual capstan >> is. It would
function very similiarly.... except it wouldnt be adjustable, and it
would not be affective in the last bit of the key stroke.  The magnet
can adjust, and stays effective throughout, but instead losses just a
little bit of its effectiveness just at about the letoff point... where
it is really no longer of consequence.

I still think the best analogy for this is the << virtual capstan and
heel>> one.

Cheers

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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