[pianotech] Keydip on Steinway pianos

[Ed Foote]

Greetings, 

>>Why is the keydip greater for Steinway S, M, and L pianosthan for Steinway B and D pianos?  The keydip for the B and D is 390mm,while the keydip for the S, M, and L is 420 mm.

    There is no proper answer that will be optimum for all these pianos.  Since the capstan placement is a resultant rather than a standard, (due trying to fit keys to cases and hammers to strings, with the capstan having to land somewhere in the mix) the Steinways are truly unique in their lack of standard action ratios.  
    The keydip is determined by how much aftertouch you want. There are a few non-negotiables.  The sharps can't be more than 1/2" above the naturals,(well, they can, but then, playing higher sharps becomes a calisthenic exercise) and they can't bury when played, so you have a limit on key travel.  The hammer shanks can't rest on the felts nor be more than 5/16" above or you risk repetition failure. So, given these limits, assuming let-off is normal, your keydip has to be sufficient to go through escapement and have some left over for aftertouch. 
   Some Steinways, with 1 3/4" blow, will need well over .400" dip, and some are much better with .380.  So the range necessary is greater than the difference between models.  I suggest you pitch all the specs for Steinways and learn how to make the compromises dictated by individual instruments. 
regards, 
Ed Foote RPT



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