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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=Erwinspiano@aol.com
href="mailto:Erwinspiano@aol.com">Erwinspiano@aol.com</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> December 31, 2003 5:56 =
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: No downbearing =
?</DIV>
<DIV><BR></DIV>
<DIV><FONT face="Times New Roman" color=#000040
size=3><STRONG> =
Jean</STRONG></FONT></DIV>
<DIV><FONT face="Times New Roman" color=#000040 =
size=3><STRONG> I agree
with the rest of these posts. Look at all the old American =
uprights you
want, but you'll only find a few with soundboards that were designed =
to have a
crown and hence downbearing & Many of them sound very nice. In my =
mind the
upright soundboard is more of a mass driven system. I.e. long strings =
and big
soundboards. These boards are tapered, thicker at the top in =
the
treble & gradually thin down to about 1/4" near the bass/ bottom =
end for
flexibility. </STRONG></FONT><FONT face="Times New Roman" =
color=#000040
size=3><STRONG> </STRONG></FONT></DIV>
<DIV><FONT face="Comic Sans MS" color=#000080
size=3></FONT> </DIV></BLOCKQUOTE>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 =
size=3>Dale,</FONT></DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>I =
suppose you have
to define what is meant by "designed to have crown...." At least until =
the
transition from hot animal hide glue to "modern" synthetic =
adhesives (for
this industry this took place between roughly the mid-20s to the =
mid-30s) all
pianos, grand or vertical, had at least some amount of =
compression-crowning.
This is regardless of what curve may or may not have been machined into =
the
ribs. Of manufacturing necessity the soundboard panels were heated =
to
approximately 120º F for several hours before ribbing. It was long =
enough to
thoroughly heat the panels and dry them to some very low moisture =
content --
and, hence, shrink them -- prior to ribbing. By definition this is
compression-crowning.</FONT></DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 =
size=3>Beyond this,
Wolfenden (at least) was using a combination of rib- and =
compression-crowning as
a standard practice when he wrote the first edition of his book (1914 =
wasn't
it?). He made no mention of his practice being in any way exclusive. =
Indeed, the
impression one gets is that it was rather common among the =
pianomakers of
his day.</FONT></DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>I =
think you have to
look at other design factors that are different between the overall =
vertical and
grand piano design practice to explain what you are finding. =
(Incidentally, my
experience does not parallel yours. Of those I've evaluated, =
verticals seem
to have about the same residual crown, or lack thereof, as grands of the =
same
vintage and life experience. Most have little or none with the =
occasional happy
exception.) </FONT></DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>A =
couple of things
you might want to consider are the generally lower quality of wood =
used in
vertical soundboards vs that used in grands and the overall length of =
the ribs.
Another factor might be the variability of the microclimate surrounding =
the
instruments. How many verticals over the past century have spent a =
winter and
summer or two backed up against an uninsulated outside =
wall?</FONT></DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 =
size=3></FONT> </DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080
size=3>Del</FONT></DIV></BODY></HTML>