I plan to build a torsion box frame that fits on top of some Krenov sawhorses I built a few hears back. Due to shop size I need something that I can break down and store when not in use. The rough size will be about 27" x 66" and I'll probably use a similar size piece of 1/2" plywood as the top skin. If it means anything I plan to make the pieces approximately 8" OC both axes.
My first question is this, if I use 3/4" plywood will 4" wide pieces be sufficiently strong. And secondly, should the notches on the long pieces and cross pieces be of equal depth? Or should I make the notches on the long pieces say, 1 1/2" deep with 2 1/2" notches on the shorter cross pieces? I cannot imagine I'd put anything heavier than a 20" x 36" x 48" carcase on this frame.