Answer to Diagnostic Quiz

Alan tune4u@earthlink.net
Thu, 8 Apr 2004 12:36:03 -0500


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These were suggested:
 
1. Misplaced bridge pins.
 
2. It's got to be friction .... Try some CLP on the bearing points ...
Check string leveling. You should also check hammer flange friction. We
here in Arizona find that the pinning is way too weak, and most of them
really should be repinned, to the point that they deviate on a hard blow
to not even hit the right string of a unison... That's my main gripe
with Baldwins right now, anyway.
 
3. Hmm, bridge separating from the soundboard.
 
4. Wood chips on the bridge?
 
5. Crossed trichord strings.
 
And the near-winner is ... #3.
 
The bridge caps separated from their bridges at the right end of the
bass bridge and on both sides of the tenor bridge notch. Since they were
still attached on one side, but not the other, they create a springboard
effect. When you turn the pin clockwise, the increased tension does not
stay in the string but presses down the springing bridge cap, so the
resulting string tension and pitch stays about the same as it was.
Loosening the pin, the springing cap rises off the bridge and, again,
there is not any change, for a while, in the string tension or pitch. 
 
Also, when the string is struck, a lot of the energy is absorbed by that
little bridge cap "diving board" instead of being solidly transferred to
the soundboard. Hence the short sustain--it really sounds like a banjo!
And there is a "bonking" sound created, too, rather like a drummer's
wood block being hit with a drumstick. 
 
I have a LOT of Hamilton studios in my area because we had a Baldwin
family dealership here in town for over 50 years and they sold a ton of
these to schools, the Army, and churches. As they age, these pianos seem
REAL prone to splitting, cracking, and separation of the bridge caps.
 
Alan R. Barnard
Salem, MO
 

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