Here are some photos of the "back saver" that I built after taking Ellsworth's class when he was still in Pennsylvania a few years ago. The pieces of wood that may come into contact with a saw chain are glued on with construction adhesive to minimize the chance of hitting a fastener screw. Overall dimensions of mine are: 42"L X 29"H X 22"W. I didn't measure his, but this is what I came up that works for me. You can see that I mounted casters on mine, as I am cutting wood my wood in the alley after rolling the rig out of the garage.