I’ve been wanting to add casters to my workbench that would be retractable, and be contained within the footprint of the workbench base. I borrowed from a few designs I found on the web. I drew it in my simple CAD program to make sure it would work. Rotating the cam handle pushes the casters down, raising the workbench enough to move.
The plywood seems plenty strong. The hinges should maybe be a little beefier, time will tell.
Currently there is a cam at each end so each pair of casters is actuated separately.
The cam turns on 1/2" lag bolt. I’m going to change the pivot attachment to something that better withstands the vertical force. The lag bolt rocks in its hole and bends. Maybe a pillow block setup. That way I could run a shaft the length of the bench base with both cams attached so the whole bench can be lifted from either end. The tradeoff for that convenience will be higher effort