Hi michiel, I agree with him too, and he agreed with me, and I agree with you. All three of your points listed below are absolutely correct in the context of how you mounted your ribs. It's just that you are talking about something a little different than I was; the forth point. I'll try to explain. What you have just described is what Del calls a "compression crowned" board. What I was trying to describe, was a board where the ribs are cut to a crown before assembly, so the *stiffness* of the rib helps hold up the downbearing of the strings. Since the rib doesn't start out flat, having to be bent to crown, it's stiffness *helps* the panel hold crown, instead of fighting it. If you had machined a crown in your ribs before assembly, you would have gotten a very similar final crown in the board, with a lot less compression stress on the panel. This would satisfy your three listed points, except for a modification of number one. The string load would then be shared between the rib stiffness and the panel. I would think this would be particularly important when you re-rib an old board because the old panel won't take the compression forces of a new one, and would need all the help it can get. This machining a crown into the ribs to help support the overall soundboard load is what Del has been describing and advocating all along, and it makes perfect sense to me too. >BTW. I agree with Tim Keenan. >The panel is NOT the ONLY thing supporting the crown. >1. The panel takes care of the pressing forces in the whole construction >perpendicular to the wood fibres. >2. And the ribs take care of the stretching forces parallel to their fibres. >3. The gluejoint keeps both opposite forces in balance. >Take one the three away and you have a problem. >Please correct me if I'm wrong. > >Michiel van Loon >Meppel >Nederland >http://www.xs4all.nl/~mvanloon >tel/fax ++31 522 255160 > Ron Nossaman
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