Instructive Challenge of the Day

[Alan]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment
Bingo, Bango, Bravo. Well done!
=20
Completely loose. I assume the mechanics were as follows: Since the =
joint
was unglued, when the hammer was thrown forward, the catcher, from =
inertia,
would slide backwards towards the backcheck. Then, when the backcheck =
hit
the catcher, energy is absorbed in reseating the catcher. It has been
demonstrated that a properly checked upright hammer actually results in =
a
slight back-bending of the backcheck wire, the whole assembly is kind of
wedged together. In our case, here, that couldn't happen and checking, =
as I
say, could not happen no matter how the backcheck was adjusted.
=20
I didn't think to check this joint until I noticed that my "perfect"
backcheck alignment was a little off after a couple of test blows. But =
the
backcheck kept pushing the catcher in so it always looked "right."
=20
Fix? Glob of Tightbond.
=20
I'm curious, Michael, had you seen this or was it just a logical guess?
=20
Alan R. Barnard
Salem, MO

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On =
Behalf
Of Michael Spalding
Sent: Monday, March 21, 2005 1:13 PM
To: Pianotech
Subject: RE: Instructive Challenge of the Day


Loose joint where catcher attaches to butt?
=20
=20

----- Original Message -----=20
From: HYPERLINK "mailto:tune4u@earthlink.net"Alan=20
To: HYPERLINK "mailto:pianotech@ptg.org"Pianotech
Sent: 3/21/2005 11:57:46 AM=20
Subject: Instructive Challenge of the Day


Upright 1890 Kranich & Bach, in very good condition after much work, had =
a
treble hammer that bobbled a bit.=20
=20
Checked regulation points, all similar to its neighbors which worked =
fine.
Held the left pedal down a bit; didn't help. Tried the key with fewer =
front
rail punchings; no help.=20
=20
Realized the hammer wasn't checking at all. Tried adjusting backcheck;
hammer would not check in any position! Made double-sure backcheck was
aligned squarely to catcher and that felt and leather were good--same as
neighboring notes.
=20
Hmmm.
=20
Perfectly squaring and aligning the backcheck was what led to the proper
diagnosis (hint) but did not improve checking at all. Repair took a =
about 30
seconds and did not require turning any screws or any regulating. In =
fact, I
used no tools at all. Hammer now checks perfectly, wherever I want to =
adjust
it.
=20
Age of piano is a hint, although the problem had nothing to do with the
brand of the piano or it's action design which is very "modern," at =
least as
far as wippens, hammers, and butts go (but don't get me started on it's
rocker capstans and short, secondary stickers that are attached with =
screws
to the capstans). The point is, this problem could occur in ANY upright =
but
is more likely in an old one.
=20
No purchase required to enter.=20
=20
Alan R. Barnard
Sendin' Out Stumpers From Salem, MO
=20


--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.7.4 - Release Date: 03/18/2005



--
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.7.4 - Release Date: 03/18/2005



--=20
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.7.4 - Release Date: 03/18/2005
=20

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/b9/95/f2/dc/attachment.htm

---------------------- multipart/alternative attachment--