This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Re: Soundboard crown ----- Original Message -----=20 From: Phillip Ford=20 To: Pianotech=20 Sent: August 17, 2003 10:23 PM Subject: Re: Soundboard crown I was also speculating about what would happen to this board if it = was subjected to a drier or more humid environment. My thought was that = in a drier environment the board would want to move up. My thought was = that the board is describing an arc. As it dried this arc would have to = get shorter, so the board would want to flatten out, which in this case = would mean moving up. You seem to think it would move down. Why do you = think that? Good question. You'll have two forces fighting each other, but = they'll not be equal forces. I think the stress interface will win. At = least until the panel self-destructs. Do you think this panel will be any more likely to self destruct than = a rib crowned soundboard with positive crown? I've no idea. It depends on the MC of the panel when the ribs were glued = on, I should think. ....I was making the assumption that any board (whether RC or CC) = with positive crown and having downbearing would have compression in the = panel. But I can see that this gets back into the arch behavior = territory again. I presume your position would be that with positive = crown and downbearing on a RC soundboard there would be no compression = in the panel because the panel can't support it and all the load is = being resisted by rib bending. There might be some. Or there might not be any. It would depend on what = the MC was at any given moment. If it is above 6.5% there will be some = nominal amont of compression. If below 6.5% there will be some nominal = amount of tension. Perhaps I can explore that in my experiment as well. But I suppose we shouldn't hold our collective breaths.... Del ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/85/d0/b9/99/attachment.htm ---------------------- multipart/alternative attachment--
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