grand hammer hanging question

[David Love]

In what way would the action not regulate?  Have you checked to be sure
that the bass hammers will go in under the pinblock with the added length? 
If you have changed the bore distance, you have changed the strike point so
it is important that you test this in the piano before you glue everything
up.  It is worth a trip back to the piano if you are not sure.  There is no
law which says that all hammers must be hung at the same distance, but it's
not a bad idea to aim for it.  The bass and tenor are not sensitive to
strike point the same way the treble is but I would be concerned about
adding so much length to the bore.  If there is an overcentering problem,
you can always rake the hammers back a little.  Some makers, by the way,
set hammers up to overcenter just slightly for various reasons.  

David Love
davidlovepianos@earthlink.net


> [Original Message]
> From: Jon Ralinovsky <ralinoj@muohio.edu>
> To: <pianotech@ptg.org>
> Date: 11/11/2003 4:59:22 AM
> Subject: grand hammer hanging question
>
> Hello,
> I'm rebuilding the action for a 1968 Kawai Model 600 (6' long).  The 
> hammers are hung in a straight line, but the distance from the hammer 
> flange center pin to the center of the hammer molding tapers from 4 
> 7/8" in the treble to 5" in the bass.  The top hammers sounded decent 
> before I took the action out of the piano; unfortunately, I didn't 
> check the case parts to see if I could move the action in or out.  Is 
> there any reason that I shouldn't duplicate the original specs?  Is 
> it important that all the hammers are hung at the same distance from 
> the hammer flange center pin?  If it makes any difference, I did 
> change the bore distance of the hammers from 2 3/16" to 2 3/8" in the 
> bass and from 1 7/8" to about 2 1/8" in the treble; this was done due 
> to the hammers overcentering and the action not being able to be 
> regulated.  I look forward to your responses.
>
> Respectfully,
> Jon
>
> -- 
> Jon Ralinovsky
> Piano Technician
> Department of Music
> Miami University
> 513/529-6548
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