>Ron, > >Thanks for you comments. I'm not sure that I understand what you mean by >panel supported. Compression crowned is panel supported. Rib crowned can be either rib supported, or a combination of rib and panel supported in any proportion. Rib crowned and supported is just that, with the panel offering little if any support. > Why would you categorize a panel that has not been severely dried, and > to which crowned ribs are attached, as primarily panel supported? It depends on the dimensions and crown of the ribs, and how do you know what the panel was dried to? If a soundboard is made with crowned ribs that by themselves aren't stiff enough to support string bearing and still retain crown, and the panel wasn't dried down enough to supply bearing support when it rehydrates, then not much of anything is supporting crown against string bearing load. If you are going to have crown remaining under bearing load, it has to come from either the ribs, panel expansion, or both. If the math says the ribs aren't doing it, it pretty much has to be coming from the panel. For instance, Yamahas are rib crowned, but an analysis of the bearing load the ribs are carrying will show that the ribs can't support the load imposed on them without the panel compression carrying a large percentage of the load. Bending force in the panel cross grain is NEVER significant to crown to my knowledge. That's why I make the distinction between rib crowned, and rib crowned and supported. Ron N
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