Help regulating sostenuto

[Paul McCloud]

Mike:
	It sounds like you need to limit the travel of the sostenuto linkage so
that the blade doesn't lift the dampers higher than key-lift height.  
	Having said that, it could also be that the sostenuto blade isn't at the
proper angle at rest.  If it's too close to horizontal (viewed from the
end), it will lift too high  when in use.  Set it about a 45 degree angle
at rest, or whatever angle it needs, so it's not lifting the dampers too
high when the pedal is fully depressed. Limit the trapwork movement (adjust
capstans or install felt blocks above the lever) so the sostenuto rod
doesn't turn too far. Set the height of the sostenuto rod so that the
sostenuto tabs peek above the blade about 1/16".  Set the proximity of the
blade to the tabs so it's not too close or too far by adjusting the
brackets in or out.  I don't know the Knabe configuration, but the Asian
pianos have brackets screwed into the bulkhead.  Yours may be held by posts
in the keybed.  
	As far as the upstop rail is concerned, you need to set it by using a
black key fully depressed.  Leave a very minimal travel of the damper while
the key is depressed.  It's ok to have the dampers lift minimally, assuming
the damper felt fully clears the strings.  If your trapwork is properly
adjusted, you won't have a problem. 
	I hope this isn't as clear as mud.  Good luck!
	
	Paul McCloud
	San Diego
	


> [Original Message]
> From: Michael Spalding <spalding48@earthlink.net>
> To: Pianotech <pianotech@ptg.org>
> Date: 12/17/2005 5:58:52 AM
> Subject: Help regulating sostenuto
>
> It's an old Knabe with non-pivoting tabs.  Regulation accomplished so far:
> 1.  Dampers lift evenly from keys.
> 2.  Dampers lift evenly from pedal, not quite as high as from keys.
> 3.  Sostenuto picks up dampers from either Key-lift height and raises them
> above Key-lift height so that when additional notes are played, the top of
> those tabs don't hit the bottom of the sostenuto blade.
>
> I'm happy with how all of that is working, but the problem is in setting
> the damper upstop rail.  When high enough to leave room for sostenuto
> operation, it's too high for normal playing.   Or I could set it for
normal
> playing, compromising touch when the sostenuto is in use.  What do you all
> do?
>
> thanks
>
> Mike
>
>
> Michael Spalding
> spalding48@earthlink.net
>
>
>
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