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questions: strength of plywood
(Henry) writes:
Imagine a rough table made of a single 4 x 8 sheet of plywood, with a
leg (4x4) at each corner. Imagine a weight placed exactly in the center
of this table.
The preliminary question is, how much will the plywood sag under the
weight?
snip
I quit doing beam deflection calculations the day I walked out of school so
I won't bore you with a lot of math which requires you to make a lot of
assumptions anyway.
The short answer is:
You can't get there from here.
Plywood without proper support, will sag of it own weight.
Build a frame using 1x4's doubled around the outside with 1/4 cross members
on 16" centers parallel to the 4 ft dimension.
Cover with a piece of 1/2" 4 ply, CDX if for storage, 2 pieces, if it will
be an active table.
You will also need 1x4's for the diagonal bracing used to keep the legs in
place.
At least that is the way I build them, only I use 2x6's for frame and legs,
but then again, It is used for 250 lb rolls of fiberglass.
HTH
--
Lew
S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: http://home.earthlink.net/~lewhodgett for Pictures
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