Brad,

Is it correct that, each time you move the tool, the 2 feet would need to be retracted using the 2 threaded knobs? In the picture I see no other way to allow the tool to rest on just the casters. Isn't this a little inconvenient for a tool that would be moved into a usable position and back against the wall frequently? Other than that, it seems like a very heavy duty mobile base.

Also, I assume that there is no reason that a piece of 3/4" plywood couldn't be attached to allow bolting a tool to the mobile base for tools like a bandsaw or drill press where having a base wider than the base of the tool itself might desirable for stability.