Touchweight Key Ratio Question

[Bill Ballard]

At 6:40 PM -0500 1/5/03, Farrell wrote:
>I suspect I should be centering the weight on a perpendicular from 
>the key directly below the capstan contact point. Is this correct? 
>In this case, the weight center will have to move toward the key 
>rear from where the capstan screws into the key. Thanks.

You're measuring the ratio of two lever arms, right? There's no 
question about where the end of the front arm is (or by convention, 
there shouldn't be). Your question is about the end of the ear lever 
arm. Why would it be anywhere but right up by the top of the capstan. 
After all it's not the point where to capstan enters the key stick 
that does the lifting, nor a point on the key stick directly below 
the top of the capstan. I'd narrow the coil slightly in the top turn 
so that the coil hangs on the the capstan's head.

It's similar to RicB's question about where the driven lever arm of 
the hammershank should be located: down the shank's center line, 
elevated to such a degree as to pass through the hammer heard's 
center of gravity, or at the hammer's strike point. The payload is 
the hammer's strike point, that's where linear measurements should be 
taken.

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

Piano Trivia: How much does Steinway's 19th brass capstan screw add 
to the balance  weight? 4.2g
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