[pianotech] Measuring Action Ratios

[Jim Ialeggio]

David, is there any chance you could confirm the actual "as functioning" 
pivot at the balance rail?

Using the key effort arm number you arrived at by the measurement you 
entered in your leverage calculation, measure the rise of the back of 
the key at full dip. Does the key back rise proportionally to the 
measured effort arm pivot point? The deeper the test dip, the more 
accurate the reading will be.

I have seen this pivot create hard to pin down measurement noise, 
because it, like the jack/knuckle interface is not a true mathematical 
pivot.

Jim Ialeggio


-- 
Jim Ialeggio	
jim at grandpianosolutions.com
978 425-9026
Shirley Center, MA