[pianotech] Upright action bracket height puzzler

[Mike Spalding]

On 9/5/2011 10:42 PM, Cy Shuster wrote:
> The patient: Kawai 601M 42" console, 1989 (US-made), clean, and 
> generally in good shape. Moved several times. Music desk missing; 
> replaced by woodworker.
>
> Symptoms: Chromatic scale from middle C up plays fine. From middle C 
> down, dip is shallow, even preventing escapement. A2 hammer also hits 
> G#2 string.
>
Cy,

You don't mention lost motion, so I am assuming it is reasonably close 
to correct and consistent across the keyboard.  That being the case, 
shallow dip is completely totally entirely a keybed problem.   Before 
you do anything with the action height adjustment bolts, I would 
thoroughly examine the keybed and its attachment to the rest of the 
cabinet and strung back.  You mentioned that the sides had separated 
from the back at the top for about 12" - did you check attachment of the 
sides to the ends of the keybed?

Mike