Wow. I just saw it, got it, grokked it. Thanks, brother. Sincerely. David A. > > When you bend a piece of wood (rib), the fibers on the convex > outside of the bend are stretched, and the fibers on the > concave inside of the bend are compressed. So if you glue an > expanding panel on one side of that piece of wood (rib), it > will stretch the rib's fibers at the glue joint as it expands, > bending the rib. Bending the rib stretches the fibers on the > outside of the curve (top), and stretching the fibers on the > top face of the rib causes the rib to bend and increase crown. > It's that simple, and has not a thing to do with an arch. The > panel will still rise and fall with humidity swings because > the compression level in the panel changes with it's moisture > content, and the resulting degree to which it stretches the > top side of the rib changes with it, changing the crown rise > as a result. Still no arch involved, it's a self contained > leverage that works without end buttresses. > > Better? > Ron N >
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