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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>
<A title=baldwin@mta-01.sk.sympatico.ca
href="mailto:baldwin@mta-01.sk.sympatico.ca">Baldwin Yamaha Piano =
Centre</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A =
title=pianotech@ptg.org
href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> September 07, 2002 3:07 =
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: New Steinway D =
problem</DIV>
<DIV><BR></DIV>At 09:24 PM 9/7/02 +0200, you wrote:<BR>
<BLOCKQUOTE class=cite cite type="cite">jolly roger wrote: <BR>
<BLOCKQUOTE class=cite cite type="cite">Hi Ric,
=
<BR> &nb=
sp;
It's a tension bar, help prevent the two struts pulling =
apart. The
beams under the board also have tension struts. That's those =
thinner
slats that go cross ways. <BR>Regards Roger <BR>
<BR> </BLOCKQUOTE></BLOCKQUOTE>
<DIV><BR>Hi
=
Ric,<BR>  =
; You
got me, on the Bell 'thingee', I have heard it called a treble =
resonator, or
just the bell. Yet I have never heard a real satisfactory =
explanation of
what is going on.</DIV></BLOCKQUOTE>
<DIV dir=ltr><FONT color=#000080>You mean the cast iron thing bolted =
to the
inside of the inner rim? It, along with the long coupling bolt going up =
through
the soundboard and the plate, mass-couples the plate hitchpin panel to =
the inner
rim. It reduces the natural tendency of the plate hitchpin panel to =
vibrate
overly much in response to the vibration of the strings.
Any vibrating in this portion of the plate will result in a
substantial and noticeable energy loss--i.e., it reduces an already =
short
sustain time through the treble region. </FONT></DIV>
<DIV dir=ltr><FONT color=#000080></FONT> </DIV>
<DIV dir=ltr><FONT color=#000080>Remember the natural vibration =
damping
characteristic of gray iron? This is just one portion of the plate where =
you can
dramatically see this characteristic in action. </FONT></DIV>
<DIV dir=ltr><FONT color=#000080></FONT> </DIV>
<DIV dir=ltr><FONT color=#000080>The bell and the coupling bolt =
are not
structural in any way, take out the coupling bolt and you can
generally hear the sustain time drop off. </FONT></DIV>
<DIV dir=ltr><FONT color=#000080></FONT> </DIV>
<DIV dir=ltr><FONT color=#000080>Which brings up the question, "how =
tight is
tight" on that bolt and nut? I don't know what the official answer is =
but I make
them snug, plus one turn. It needs to be tight enough to efficiently =
couple the
two together but not so tight as to affect bearing and/or break =
something.
</FONT><FONT color=#000080></FONT></DIV>
<DIV dir=ltr><FONT color=#000080></FONT> </DIV>
<DIV dir=ltr><FONT color=#000080>Del</FONT></DIV></BODY></HTML>