>Keeping the laminations all in same direction is an idea that goes >other directions then worrying about cracks. > >What I was curious about and still havent gotten a straight up >answer too, is whether or not a laminate board laminated over a >curved caul with the grain all going in the same direction could >achieve the same crown and crown support as a ribbed board with ribs >going perpendicular to the grain. I.e. the strength of the laminant >panel along the grain compared to the strength of the ribbed board >along the ribs. > >Cheers >RicB If you are thinking about the application of a laminated panel without ribs, this wouldn't have sufficient stiffness to support the downbearing load if the panel thickness was a standard nominal thickness (say between 7-9 mm). A panel on its own would have insufficient sectional depth to achieve the stiffness required. If you were to use a thicker panel, at some point you would achieve a satisfactory stiffness but the overall mass of such an assembly would greatly exceed the mass of a conventionally ribbed panel of normal thickness. One of the principal structural benefits of the ribs is that it gives the overall assembly a sufficient sectional depth that the panel and ribs can, together as a unit, provide the necessary stiffness. I'm not suggesting that a laminated panel wouldn't have a higher stiffness than an equivalent thickness solid panel. It certainly would, but not enough to support downbearing in its own right. If you find this hard to believe just laminate a little section for you own investigation. Best, Ron O. -- OVERS PIANOS - SYDNEY Grand Piano Manufacturers _______________________ Web http://overspianos.com.au mailto:ron@overspianos.com.au _______________________
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