[pianotech] Measuring Action Ratios

[Jim Ialeggio]

David Love wrote:

<Shank Ea is measured from the hammer flange center pin to the center of 
the knuckle core (measured along the shank) .
<Shank Ra is measured from the hammer flange center pin to the center of 
the hammer molding (measured along the shank).

Did you mean to write this David???

Shank Effort arm, or in my terminology shank lower lever, is center pin 
to full projection of knuckle...center pin to full projection of the 
knuckle is the hypotenuse of a right triangle rather than the adjacent 
side you called out.

LIke-wise, Shank Resistance arm, on in my terminology shank upper lever, 
is shank center pin to strike point on the hammer. Again, it is a 
hypotenuse, of a right triangle, rather than the adjacent side you 
called out along the shank.

Perhaps this is what is messing with your numbers???

Jim Ialeggio

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