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<DIV><FONT face=Arial>David,</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>These are all original parts and I did check jack
clearance, which is good. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>One thing you mentioned is very interesting. In order to
get the proper after touch, I had to set the key dip at 10mm which is a little
more than Steinway recommends. If all else fails, I will reset the touch to
Steinway specs in the bass to see if that helps any, but I'm sure the problem is
elsewhere. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I also agree;</FONT></DIV>
<DIV><FONT face=Arial></FONT><FONT face=Arial><EM>(snip)</EM></FONT></DIV>
<DIV><FONT face=Arial><EM>"</EM></FONT><FONT face=Arial><EM>the buckskin &
felt on the newer checks offer almost no resilience </EM><EM>the profile at the
top of the backcheck face forces the tail to bounce off, as you describe in
your post"</EM></FONT></DIV>
<DIV><EM><FONT face=Arial></FONT></EM> </DIV>
<DIV><FONT face=Arial>Al Guecia</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>----- Original Message ----- </FONT>
<DIV><FONT face=Arial>From: "David Skolnik" <</FONT><A
href="mailto:davidskolnik@optonline.net"><FONT
face=Arial>davidskolnik@optonline.net</FONT></A><FONT
face=Arial>></FONT></DIV>
<DIV><FONT face=Arial>To: "Pianotech List" <</FONT><A
href="mailto:pianotech@ptg.org"><FONT
face=Arial>pianotech@ptg.org</FONT></A><FONT face=Arial>></FONT></DIV>
<DIV><FONT face=Arial>Sent: Sunday, March 16, 2008 1:02 AM</FONT></DIV>
<DIV><FONT face=Arial>Subject: Re: Steinway M Backcheck
Problem</FONT></DIV></DIV>
<DIV><FONT face=Arial><BR></FONT></DIV><FONT face=Arial>> Mike -<BR>> I
think the self-locking taper image is an apt analogy. I had <BR>>
occasion this afternoon to be working on a recent vintage Steinway D <BR>>
which has what I think is the same condition that Al has described, <BR>> and
I would just add a few details to my previous summary:<BR>> - the buckskin
& felt on the newer checks offer almost no resilience<BR>> - the profile
at the top of the backcheck face forces the tail to <BR>> bounce off, as you
describe in your post.<BR>> - one other regulating parameter can have a
significant impact on <BR>> checking: if either the dip is excessive, or if
the particular <BR>> combination of parts employed in rebuilding force the
jack to firmly <BR>> contact the butt felt in the rep lever window, the
resulting friction <BR>> can absorb enough energy from the hammer rebound to
compromise checking.<BR>> <BR>> As for the particular version of the
problem in the low bass, the <BR>> requisite stiff, heavier spring might have
something to do with it. Or not.<BR>> <BR>> David Skolnik<BR>>
<BR>> <BR>> At 10:45 AM 3/15/2008, you
wrote:<BR>>>David,<BR>>><BR>>>Good comprehensive summary of
the issues, and I agree with you on <BR>>>all points, particularly the
folly of roughing the tails or check leather.<BR>>>If roughing improves
checking, there is an unresolved problem somewhere.<BR>>><BR>>>I
like to think of the backchecks and tails as a self-locking
taper.<BR>>>This is the same mechanism that keeps the chuck in your drill
<BR>>>press. As long as there is some amount of friction, no matter
how <BR>>>small, there is a taper angle below which the taper will lock,
and <BR>>>above which it will fall apart. In the context of
backchecks, if <BR>>>the check is laid way back then adjusted to contact
near the tip of <BR>>>the tail, the hammer will bounce off the
check. Go to the other <BR>>>extreme, with the check near vertical
and contacting up near the <BR>>>shank, and the hammer will check, but not
at a consistent height: <BR>>>the harder you play, the lower it will
check. Somewhere in between <BR>>>is the optimum, where the hammer
will reliably check, and will be <BR>>>difficult to push further
down.<BR>>>Admittedly, there are pianos where this sweet spot is not easy
to <BR>>>find, especially in the low
bass.<BR>>><BR>>>Mike<BR>> <BR>> <BR>></FONT></BODY></HTML>