Virtual Capstan

[Richard Brekne]

Ron Nossaman wrote:

> > > I doubt any significant friction effect, though there may be. It's
> > > primarily just leverage. Using a random action model I have on hand for
> > > dimensions, 1g placed on the key where the magnet would be adds 0.79g to
> > > the touch weight.
> >
> >How can this be.... ? adding 1 gram to the key where the magnet is has to
> >result in less then half a gram at the key front. In fact since the KR is only
> >0.45 at that spot... it should add only 0.45 grams extra weight to the
> >existing TouchWeight.
>
> Sorry, I misspoke. I meant equivalent at the capstan. That's how I set up
> my spreadsheet and didn't convert when I wrote this.
>
> > > 1g on the wippen where the magnet would be adds 1.27g to
> > > the touch weight for a net +2.06g to the touch weight. 1g of magnetic lift
> > > adds 0.79g, and removes 1.27g, for a net loss of 0.48g to the touch. So 1g
> > > magnets must produce at least 2.06g lift to break even.
> >
> >In the measurements I just took, adding the 2 grams of the whippen magnet
> >assembly increased the whippen radius weight taken at the cushion by 2.4
> >grams... which gets multiplied by the key ratio of 0.51 yielding 1.22 grams
> >increase at the key front. Thats half what you figure here. This is born out
> >by directly weighing them... I put 2 magnets at that point after zeroing the
> >scale. The magnets weighed 2.5 grams and the change in the scale was 1.1
> >grams.
> >
> >My measurements show a total increase of dead weight mass of 4.5 grams, 2.5 on
> >the key 2 on the whippen, translating to an increase at the front of the key
> >to the existing touch weight of 2.32 grams, and this for 2.25 times the amount
> >of mass you are figureing on
>
> Again, effective weight.at the capstan. When I do something inside out, I'm
> consistent.

Grin... consistancy is important !...

No.. but this is fine... so long as we are on the same page. This all works pretty
much out as my measured and calculated results did..... roughly, the weight about
half the total mass due to the magnets and assembly at the front of the key.


--
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