On Wed, 13 Feb 2002 09:27:29 Joseph Garrett wrote: >I think that, if the rib is laminated in a cull of the proper curvature, >then the rib will hold that curvature better, although it is no "stiffer" >than a plain rib. It's resistance to straightening will be greater, but the >mass will be the same. My expertise also comes from boat building. However, >hydroplanes was my mania. The "stressed" skin construction and laminated >ribs was a favorite of these high stress rockets. Correct me if I'm wrong, >but isn't our main objective with the rib to maintain the >curvature/counter-tension against the downbearing of the strings? Just my >view of the whole mess. <G> >Regards, >Joe Garrett, RPT, (Oregon) > Joe, This is essentially the same thing that Dale was saying. I think you may have something here. It would be interesting to do an experiment on this. Take a typical solid rib and a laminated rib designed to have the same stiffness and having the same length, support them at their ends, and hang a load in the middle. Probably the best way to insure that the stiffness is supposedly the same would be to take a typical long rib, cut it in two pieces and then cut one of those pieces into strips and glue it back together. That way both ribs are made of the same piece of wood, so to speak. Check their initial deflections and see if there is a difference in deflection, even though they are supposed to be the 'same' stiffness and monitor the deflections of the two over the space of a few months and see if one is more resistant to creep or permanent set than the other. Phil F --- Phillip Ford Piano Service & Restoration 1777 Yosemite Ave - 215 San Francisco, CA 94124 Go Get It! Send FREE Valentine eCards with Lycos Greetings http://greetings.lycos.com
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