Tension
>> & compression go hand in hand in the hammer pressing process.
>> As I stated, & piano hammer makers can tell you, that too much
>> tension
>> can
>> be achieved during pressing in the outer layers of felt and it can &
>> will rip
>> open in the crown. This is the elastic limit of the felt.
----- Original Message -----
From: "antares" <antares@euronet.nl>
To: "Phillip Ford" <fordpiano@earthlink.net>; "Pianotech"
<pianotech@ptg.org>
Sent: Tuesday, May 18, 2004 2:39 PM
Subject: Alfred Dolge would smile upon us
I think this is the problem in Yamaha hammers. As they wear, the crown
"blooms", i.e., spreads wider, making the hammer pear-shaped rather than its
original "diamond" shape. Anytime I've filed hammers on a Yamaha, not only
is it difficult to find a "layer", but the crown spreads apart even worse
from the filing than it already had been from the string cuts. So the inner
part of the hammer must be compressed too much or the outer part is
stretched too much, or both.
If the tone is too bright after the filing, then any voicing with
needles near the strike point (even if it's not right ON the strike point)
makes the crown spread apart even more. It's very frustrating and I'm not
sure how to handle this problem.
--David Nereson, RPT
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