stuck

[A440A@aol.com]

Paul wrote:

>I was asked to regulate a Steinway B.  
>When the hammers drop after releasing the keys they hit the top of the back
>checks.  
>The other problem is the jack. With the dip at .375, blow at 1 5/8", the back
>of the jack is being pressed into the cushion in the back of the balancier
>window. It is literally captured between that cushion and the let off button.
>Increasing either the dip or blow distance makes the problem worse.

Greetings, 
   At rest, how far are the hammershanks off the rest felts, and what distance
are you using for let-off? Is the action spread correct, and what is the
relationship of the jack angle to the knuckle, at rest?  Are the hammer tails
cut way far under? are the hammers glued at 90 degrees to the shank?   There
is a lot of info needed to determine where this problem is. You may have an
action that needs a very short blow and dip.  What is the keybed to string
height?
   In general, If you have the jack trapped at the bottom of the keystroke,
there is too much dip for the amount of hammer blow.  Some compromises will
have to be made here.  It will be helpful if you follow Stanwood's metrology
measurment, so that you know what your action ratio is.  I would imagine this
piano was made between 1963 and 1984?  
Regards, 
Ed Foote