There was some mild interest in my homemade thickness sander a few weeks back so here's some pics to help get the idea across. It's a 1hp with a 5" x 18" diameter drum turning in the neighborhood of 875 rpm. Adjustment is done by an acme screw threaded up under the riser board. Total cost was about $50 for the motor and bearings. the rest is scrap, trash, and old stuff I've been saving for years. About 2 afternoons of work and this is what I've got.