[CAUT] Steinway repetition center pin height

[Chris Solliday]

Steinway repetition center pin heightsorry hit the send button by mistake,
to continue
...5 1/8" from the centerpin of the hammershank flange to the center line of the hammer moulding.
Also
The action stack height, as determined by the thickness of the mounting blocks. This action height is unique for each instrument, and is the result of the individual string height for a piano. String height variables are the result of the plate fitting and belly operations.
SET ADJUSTABLE GAUGE for the string height at note #62.
the gauge is set up in such a way that the relationship between the action stack and the string height is maintained.
 : this ensures, A) the proper BLOW distance at the same time the hammershank is properly off the rest cushion (just slightly).
 : the proper HAMMER ROTATION is needed to minimize overstriking or shallow striking condition.
DETERMINE NEEDED HEIGHT OF MOUNTING BLOCKS
Plane bass and treble action mounting blocks so that the two flange centerpins are in alignment with the gauge's referance points.
Fit center wedges so that the front and rear feet of each action hanger SLIGHTLY rests on the blocks, at the same time, maintaining the STRAIGHTNESS of the frame. Continually check for straightness with the straightedge on top of the hammershank flanges."
That is from the horse's mouth.
We have found that sometimes the mounting blocks have been trimmed by others or for other purposes such as stopping "catastrophic action failure."
In general if you raise (shim) or lower (plane) the height at the center pin you should do the opposite to the front foot so as not to throw the hammer fore or aft. You want to rotate as you raise or lower. The pin is the pivot point. 
I hope this a help. The bore is expected to be 2 1/4" in the bass and 1 15/16" throughtout the treble. We do not find varying the bore to be a good idea, however, sometimes the strike line is not straight. Hammers could vary around the 5 1/8" spec.
In other words vary the stack height before fudging anything else based on your string height average compared to spec.
 If you would like more info, like current boring angles etc., let me know. I am leaving for KC tomorrow. And will not be able to help while I am there.  
Best of luck.
Chris Solliday
  ----- Original Message ----- 
  From: David Brown 
  To: caut at ptg.org 
  Sent: Tuesday, June 12, 2007 2:20 PM
  Subject: [CAUT] Steinway repetition center pin height


  Dear List--

  Anyone know offhand the spec for the center pin height from the key bed for a S&S rep? This is a relatively new model D. Or an even better question is - how to determine if an action stack is tipped front to back? We are re hammering our American and sample bore distances and subsequent regulation leave us wanting more.  We plan to continue on by checking convergence etc. Enquiring minds and all!

  Thanks in advance-

  David

   
  David C. Brown 
  Arizona State University
  School of Music
  Piano Technician
  1-480-965-6760
  david.c.brown.2 at asu.edu

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