Your thread got me motivated and I was needing a project to test my new Powerarc 300 on.
I went to the steel yard Tuesday and bought a 4x10 sheet of 1/2" plate and 80' of 2.5" x 3/16 square tube. I laid the plate on the shop floor and built the frame on it upside down then flipped it over. Aside from the the metal I bought I added some 2" x 3/16" angle and a piece of pipe in the middle for support. Probably it is overkill but I wanted it sturdy and no flex. Weight of it is about 1400 lbs. I did not add any levelers on the feet or wheels but it sits good and level with no wobble. The thing is nice I don't think you could budge it if you wanted to. I am sure looking forward to being able to work on it and not on the floor anymore. My knees are killing me from this build.