uprights, hammer boring

[Paul McCloud]

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When I was in Reno, I attended a class by a gentleman (Mr Vale?) from
Austin, Texas.  He has developed and patented a system for installing
vertical hammers which is as good as it gets.  I'll try to find his name
and the handouts he had.  The system included many jigs for setting the
different parameters, such as bore, rake, etc.  His methods and jigs are
for sale (not cheap!).   He had many other jigs and tools for sale, and
he passed out his catalog to anyone who wanted it.  He does a lot of
upright restorations, and might be able to give a definitive answer.   I
just found his name in the 2002 directory: Raymond J. Vale, email:
rayvale@tooeasy.net.   

            Paul McCloud

            San Diego

 

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On
Behalf Of Greg Newell
Sent: Wednesday, March 12, 2003 9:14 PM
To: Pianotech
Subject: Re: uprights, hammer boring

 

Keith,
        I believe that Newton Hunt wrote something about this a while
back on this list. You could search for it in the archives. If you find
it feel free to repost. I'm sure many would be interested. I seem to
remember that bore distance was the same as a grand in that butt flange
center pin to string is the bore distance. As far as rake goes I really
don't remember. I don't replace a great deal of hammers myself. 
        This brings up a question for me that perhaps someone can
answer. Although I don't replace many sets of hammers on uprights I
presently have occasion to replace a set on an old Gulbransen upright. I
tried to measure from the butt center pin to the string and I just
couldn't get a measuring device in there to take the measurement. Anyone
have a tip on what I could use to get a good reading? Might be too late
for this set but I'd sure like to know for the next one.

Greg


At 05:28 PM 3/12/2003, you wrote:




I gave the technical on hammer boring at the chapter meeting, (with the
back-up of the RPTs at the meeting), and nobody could explain what the
criteria would be for determining hammer bore distance and rake for
optimum performance on an upright. Sure, go by the original is an easy
answer but what if it looks as if somebody who "hadn't a clue" put those
hammers on. I have 3 old uprights here, a 1909 Smith and Barnes, a 1911
A.B. Cameron, and a 1906 Kohler and Chase. The first two, the hammers
shanks are close to parallel with the string plane, and the rake is
minimal. Or, worded differently, the bore distance is the distance from
the hammer flange center pin to the string plane. Rake is 1 or 2
degrees. 
The Kohler has much more rake, 5+ degrees and the shank is at the
similar angle to the string plane so the hammer is square to the string
plane when it hits.
Why?
Should I be looking at the angle of the jack to the whippen at the start
of lift? The hammer butt/jack angle at let off?
Or maybe it was something simple, like the little bit more clearance
that could be had by moving the action closer to the strings.
Anybody?
Keith Roberts

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Greg Newell
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