[pianotech] Hammer Blow

[Dale Erwin]

Hi Floyd
 Dittos on Jons post.
  
  And just the squish factor of the avergae supply house front punching changes the feel and amount of overall dip/aftertouch based on touch pressure. They squish as much as .035 compared to .015 for Jurgens crescendo punchings. If you're looking for more precision in key dip/aftertouch its only logical use the latter to reduce errors from variables


Dale Erwin R.P.T.
Erwin's Piano Restoration Inc.
 Mason & Hamlin/Steinway/U.S. pianos
www.Erwinspiano.com
Phone: 209-577-8397

 
  





-----Original Message-----
From: Jon Page <jonpage at comcast.net>
To: pianotech <pianotech at ptg.org>
Sent: Tue, Oct 9, 2012 4:29 am
Subject: Re: [pianotech] Hammer Blow


 >This week I'm going to see what happens to my hammer line if I set 
hammer blow to achieve a specified amount of aftertouch.  I've set the 
key height, >key dip and letoff.  I'll put the action in the piano, use 
a .045 punching with a notch cut out so I can slide it onto the front 
rail pin over the cloth >punching with the key installed, and set the 
hammer blow for each of the white keys such that a weight on the key (I 
forget how many grams, and I'm >not in the shop to check) brings it 
almost to let-off, and a slight downward tap on the key will take it 
through let-off. Theoretically, the straightness of >the hammer line I 
achieve with this procedure should allow me to evaluate how successful I 
was in setting even key dip and consistent aftertouch.

Your hammer line will become erratic by doing this because of the 
slightly different Key Ratios between notes. That procedure is what you 
do to set an even touch with a priority given to aftertouch. But to do 
this, you alter the dip not the blow distance. Keys level, hammer line 
level, key dip slightly uneven. The pianist feels a even aftertouch and 
not an uneven key dip. Altering the blow on an individual basis will 
introduce volume discrepancies brought on by varying blow distances.

Aftertouch calibration by varying dip slightly is essential to a smooth 
feeling action.

-- 
Regards,

Jon Page


 

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