Regulating Key-Dip

Thomas Cole tcole at cruzio.com
Sun Apr 8 20:14:15 MDT 2007


The sharps at rest should be at 1/2" above the naturals. If you 
increased the dip to 1/2", the sharps would bury in the naturals which 
is incorrect. That's the reason for .390" ±. I think spinets may have a 
little more dip.

Key dip is an independent variable. This is what an experienced pianist 
expects so we start with that. The dependent variable is hammer blow 
distance which should be sufficient to allow the jack to clear the 
hammer butt buckskin by about 1/32".

If the hammers have been filed such that the blow distance has 
increased, the solution is to shim under the hammer rest rail to 
decrease the hammer blow and not change the key dip if it is correct.

Tom Cole

mps at usol.com wrote:

>I have an old Hackley upright in which the hammers have probably 
>been shaped a couple of times. I have had no problems with the 
>regulation on the instrument.
>However,  I think that I read someplace that the key-dip on this could 
>be adjusted as low as 1/2".
>My question is if I do adjust the white keys to a 1/2" key dip, how 
>would I measure the black keys so that they also have the same 
>amount of dip?
>Also, what are the deciding factors of exactly how deep to set this 
>key-dip?
>
>Thank you
>
>Mark D.
>Montbriand
>
>
>
>  
>
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