[JamesCH95]

Originally Posted by Don Rotolo

You mean they should cut up a pair of your pants? Hopefully not while you're still wearing them...

Seriously: Good advice. A lightweight but low-compressibility core will enhance the stiffness of the layup by bringing the tensile fibers (fiberglass or kevlar) further from the center of bending. Balsa is good, high-density styrofoam (expanded polystyrene) works very well, even 1/4" luan plywood is good. 1/8" is a good thickness to experiment with.

We've made some experimental layups using 1/16" aircraft plywood and 2 layers of 3 oz fiberglass, laid up at a 45 degree bias using marine epoxy and pressed tightly for cure using a heavy weight (iron barbell weights), the stuff was incredibly strong. Only problem is finding large sheets of 1/16" plywood, we used small pieces made for the hobby market.

Thanks. Have you ever used those plates on your robot? It does sound like very durable construction.

OP, FWIW: typical commercial wood-cored composites orient the wood grain normal to the surface of the plate, typically called "end grain" orientation. This orients the core in a way to take maximum advantage of it's shear strength, the skin will support tensile/compressive loads.