Let me restate the question

[Overs Pianos]

>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
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Web http://overspianos.com.au
mailto:ron@overspianos.com.au
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