[CAUT] S & S D rest cushions

[Jeff Tanner]

Hi Fred,
"Catastrophic Action Failure" happens because checking is too low, hammer flange, jack or rep lever pinning too sluggish or rep springs doing absolutely nothing at all.  Not because of rest cushions.  We shouldn't even need rest cushions or rails.  I've had the same issues with hammer shanks having to be so high above the rest cushions to get aftertouch with reasonable keydip and never one issue of catastrophic action failure unless one of the above was the cause.

If you had a Steinway with shanks on the cushions, you may have had a mismatch of Hamburg/NY Pre '84 parts.  That's the only way I've ever seen that problem occur.
Jeff
  ----- Original Message ----- 
  From: Fred Sturm 
  To: caut at ptg.org 
  Sent: Friday, August 14, 2009 1:56 PM
  Subject: Re: [CAUT] S & S D rest cushions


  On Aug 14, 2009, at 9:48 AM, Marcel Carey wrote:


    Hi, this is what I found in a S & S D that was rented from the Mtl Dealer. I suspect major geometry problems as the shanks were really high from the original cushions. But... was this the real solution? Repetition was realy problematic and regulation in general wasn't better than the solution adopted by the previous "tech".
     
    Some days are worst than others.
     
    Marcel Carey
    Sherbrooke, QC


  Here is my temporary solution to the same (more or less) problem. In this case, the bore distance was too short, and it had the added attraction of the tails being too short, so checking was about 7/8". I had peeled cushions on a Steinway grand with the opposite problem (hammers resting on the felts with a decent blow distance), so I just took the peelings and tack glued them on those red cushions. Worked fine for a few years. This last summer I finally replaced the action parts (80s teflon), and have a nice playing piano.
  In any case, though, it is better to have those cushions close to the shanks, regardless of the other problems that probably go along with shanks too far above the cushions. (I had had problems of what Eric called "catastrophic action failure" in a thread a good while back - notes that would suddenly not play because of the jack not being able to get back under the knuckle). A better solution might be to shim up the action frame, depending on what effect it might have on other things. A little experimenting would reveal whether or not it would be more helpful than harmful (install shims temporarily, regulate a few notes).
  However, in your case, with such a relatively new piano, I would want to do some serious investigation. It looks like some pretty incompetent techs have been involved, putting graphite over emralon being one bit of evidence, another being the strip of red felt. 

  Regards,
  Fred Sturm
  University of New Mexico
  fssturm at unm.edu








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