<HTML> In a message dated 11/13/03 1:32:52 AM, Erwinspiano@aol.com writes: <BLOCKQUOTE CITE STYLE="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; = MARGIN-RIGHT: 0px; PADDING-LEFT: 5px" TYPE="CITE">What do I mean? This = will answer Crashvalves question as well. When pre-stressing a board with go= od legitimate crown values as I described, it does require having the plate = in and secured with bolts & screws. Enough so that when driving the mapl= e wedges between the struts and the bridge tops it (the plate) doesn't fle= x. </BLOCKQUOTE> Well drat, I was hoping you were talking about iterating some trigonometry t= hat would use the string scale and degrees of downbearing and yield a down b= earing in pounds. This then loaded onto the bridge to test board deflection.= At this stage of soundboard build, the only variable left to tweak is plate= set/downbearing, and knowing the amount of deflection expected from a board= might be a good indicator of stiffness ? 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 ? I have seen an un-mounted s= oundboard calipered using a dial indicator clamped to the top of a jigsaw (s= ans blade) but in the piano is different. I finished putting a .020 probe in= to the end of a depth mike</HTML>