>Del or you or someone also wrote a while back some examples of how much a >rim might commonly move by every-day events - like someone leaning against >it, or the size change caused by a humidity change. As I recall these >movements easily were greater than the change in rib length between curved >and straight. Any recollection of this? Yes, but not the numbers. Anyone who's interested can take some measurements of their own in a piano they have the soundboard out of and see what kind of pressure it takes to deform a rim 0.008", or a belly rail 0.0004". >I readily see that the case does not maintain the soundboard crown - the >crown is from curved ribs and/or panel compression. But could a spreading >rim tend to flatten the soundboard (like the Chris Robinson experiment)? > >Terry Farrell I certainly don't see how, and this is the first I've ever heard of Chris doing this. I don't buy it. Ron N
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