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<DIV>In a message dated 11/13/2003 6:59:10 PM Pacific Standard Time, Crashva=
lve@aol.com writes:</DIV>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue =
2px solid"><FONT color=#000000 size=2 FAMILY="SANSSERIF"><FONT face=
=Arial>In a message dated 11/13/03 1:32:52 AM, Erwinspiano@aol.com writes:=
<BR><BR><BR></FONT>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000=
ff 2px solid; MARGIN-RIGHT: 0px" cite="" TYPE="CITE"></FONT><FONT color=
=#000000 size=2 FAMILY="SANSSERIF"><FONT face=Arial>What do I mean? =
This will answer Crashvalves question as well. When pre-stressing a board wi=
th good legitimate crown values as I described, it does require having the p=
late in and secured with bolts & screws. Enough so that when driving the=
maple wedges between the struts and the bridge tops it (the plate) doe=
sn't flex</FONT></FONT></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue =
2px solid">
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000=
ff 2px solid; MARGIN-RIGHT: 0px" cite="" TYPE="CITE"><FONT face="Times=
New Roman" color=#000040>Dale</FONT><FONT color=#000000 size=2 FAMILY=
="SANSSERIF"></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue =
2px solid"></FONT><FONT color=#000000 size=2 FAMILY="SANSSERIF"><FONT =
face=Arial>Well drat, I was hoping you were talking about iterating some t=
rigonometry that would use the string scale and degrees of downbearing and y=
ield a down bearing in pounds. This then loaded onto the bridge to test boar=
d deflection. At this stage of soundboard build, the only variable left to t=
weak is plate set/downbearing, and knowing the amount of deflection expected=
from a board might be a good indicator of stiffness ?</FONT></FONT></BLOCKQ=
UOTE>
<DIV><FONT face="Times New Roman"><FONT color=#000040> <FONT size=
=3><STRONG> >>>></STRONG></FONT><STRONG><FONT size=3>You get=
trig from Del & others. From me, well there are simple ways to figure a=
ngle of deflection. It's the rear length of the string from the front bridge=
pin to the aliquot times . 026 for 1 & 1/2 degree. .017 for 1 degree. T=
his will give you distance bearing specs. I believe the average bearing forc=
e for a typical 160 lb. tension scale is a bout four pounds per string at 1&=
amp; 1/2 degrees deflection. What I know is that pre stressing the board usu=
ally yields a similar deflection after it's strung. It's simple to mea=
sure from the strut down to the bridge top after the tension is on & I u=
sually find about the same amount of squash that pre-stressing yielded.</FON=
T></STRONG></FONT></FONT></DIV>
<DIV><FONT color=#000000 size=2 FAMILY="SANSSERIF"><FONT face=Arial>=
Sorry if this seems overly minute, but I seem to get farther along in =
just about any piano task if I can mike it up. BTW how did you measure that =
.400 panel ?</FONT></FONT></DIV>
<DIV><FONT color=#000000 size=2 FAMILY="SANSSERIF"><FONT face=Arial>=
<FONT size=3><STRONG> I had the plate out & measured at the nose =
bolt holes.</STRONG></FONT></FONT></FONT></DIV>
<DIV><FONT color=#000000 size=2 FAMILY="SANSSERIF"><FONT face=Arial>=
<STRONG><FONT size=3> </FONT></STRONG> I have seen an un-mounte=
d soundboard calipered using a dial indicator clamped to the top of a jigsaw=
(sans blade) but in the piano is different. I finished putting a .020 probe=
into the end of a depth mike</FONT></FONT><FONT color=#000000 size=2 FA=
MILY="SANSSERIF"></FONT><FONT face=Arial> </FONT></DIV>
<DIV><FONT face="Times New Roman" color=#000040> Glenn</FONT></DIV>=
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