Virtual Capstan

[Bill Ballard]

At 11:50 AM +0200 6/23/03, Richard Brekne wrote:
>I think you missed something somewhere Bill. Rons description bear out quite
>clearly what my BW measurements show. The leverage does change.... in terms of
>weight. As it must.

I agree that once you install the magnets, and enter their force 
vector into the system, that in the dimension of mass, the leverage 
has changed. As it must. In the linear (or angular dimension), 
nothing has changed. So whatever lightening of the load the magnets 
accomplish, this won't require resetting blow, dip and aftertouch. 
Nobody is surprised anymore that these two measurements of action 
ratio are independent of each other. (Actually, it's just that the 
weight-based measurement can be changed without altering the the 
actual lever arms. It doesn't work the other way.)

At 2:21 PM +0200 6/22/03, Richard Brekne wrote:
>BobDavis88@aol.com wrote:
>>Imagine holding a 10-lb. sack of sugar. You feel it as ten pounds. 
>>Now attach a powerful magnet to the bottom of the sack, and a 
>>powerful repelling magnet in your hand. The magnets might not 
>>touch, but is the sugar lighter? No. It might even float a few 
>>inches in the air, but you still feel ten pounds of weight in your 
>>hand, the same as if it were sitting on top of a coil spring which 
>>you were holding.
>>
>>
>This is exactly true. Given a strong enough magnet it could float in 
>the air... which is much the same thing as raising the sugar with a 
>small post.... except the post would be visable, and non 
>compresseble. Which is why again I call this a virtual capstan / 
>heel.
>
>It functions more like putting a secondary capstan and heel on the 
>key and whippen then anything else... again except for the 
>compressebility.

Why is it doing anything more than placing an upwards vector right 
next to the downwards vector at the capstan lift point. I thinks it 
function very similarly to a helium balloon tied to, and lifting up 
on the wippen. If one views the effect of the magnets as being just 
another force vector, then it can be generalized as having a net 
effect on the capstan. When viewed in the dimension of mass, the 
magnets simply make the second point at which force enters the 
system, to lift the action parts. The first point being the front end 
of the key.

Yeah, I know, it's not fair of me to fire all this of after you've 
gone to sleep. <g>

Bill Ballard RPT
NH Chapter, P.T.G.

"We mustn't underestimate our power of teamwork."
     ...........Bob Davis RPT, pianotech '97
+++++++++++++++++++++