<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1106" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV> </DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=Richard.Brekne@grieg.uib.no href="mailto:Richard.Brekne@grieg.uib.no">Richard Brekne</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> August 19, 2003 10:13 = AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: More on soundboard = crown</DIV> <DIV><BR></DIV>  <P> <BLOCKQUOTE TYPE="CITE"> <DIV dir=ltr><FONT face="Comic Sans MS"><FONT color=#000080></FONT></FONT></DIV></BLOCKQUOTE>Hi Del... = actually... I was rather thinking (again perhaps another one of those bunny trails...) = that perhaps one could add about a 1/8th inch thick strip of left over = sounboard material to the top half of the rib, grain in the same direction as = the panels. If it was dried to say 6.5 MC prior to attachment to the = rib... and the soundboard was dried to say 4.5 MC why wouldnt this tend to sort = of buffer the ribs cross grain constraint ? When taking on humidity this layer = would get slightly compressed by the rib... and since its grain is in the same orientation of the panels it wouldnt force that into nearly as much compression.... er.. I think :)... If there was not enough crown you = could rib crown enough to make up the difference. I suppose you could rib crown = to begin with.. but if this provided a kind of solidly glued  << = slip joint >> , and if there was some good reason to dry out the panel to = 4.5 MC as long as one could avoid exceeding the stress limits... well... = Anyways.. I'm just fooling with ideas in attempt to better sort out what does and = doesnt happen. yes ?? <P>RicB </P></BLOCKQUOTE> <P dir=ltr><FONT face="Comic Sans MS" = color=#000080></FONT> </P> <P dir=ltr><FONT face="Comic Sans MS" color=#000080>I fail to see = the point. Any time you dry a soundboard panel that far down there are going to be = compression problems later on. Period. There is no way to "buffer" it. Unless, of = course, you leave the panel free of constraints and let it float free. I.e., = ribless and unattached. It is the MC in the panel--actually, the lack thereof--that = is the problem. Since leaving the panel free and unattached is not a practical = solution the simplest way to avoid the problem is to not dry them out that way.</FONT></P> <P dir=ltr><FONT face="Comic Sans MS" color=#000080>This is = nothing I'm even remotely interested in working on. As you say, why not just crown = the ribs? It's a simple and effective solution. It's a well known technology = that has been around long enough that its working characteristics and advantages = are fairly well known. And, by now, it's a technology that should be well = accepted. Of course it is by many in the industry. And it would be by many more if = it weren't for the monumental weight of tradition and design lethargy = endemic to the industry. Personally I just don't see any reason to keep beating = away at what I see as a dead horse. It's not going to come back to life--it's = just going to keep right on being dead. The best you can do is tenderize the meat a = little. Life, and most of the piano industry, moves on.</FONT></P> <P dir=ltr><FONT face="Comic Sans MS" color=#000080>As always, = you're encouraged to design and construct an experiment. I'll not bother...I'm quite = content with the rib crowning techniques I've worked on and refined over the years..</FONT>  </P> <P dir=ltr>Del</P></BODY></HTML>