I seem to be caught in an endless list of to-do's for the shop that have little to do with actually making something. My Disc / Spindle unit didn't come with a mobility option. Not really a problem, I just factored in a 'wheelbarrow' style solution when I built the drawers into the base. Due to where the sander lives, I found myself moving it about more than I thought I would. This made me unhappy since I more often than not grabbed it by the table even though common sense tells us not to lift our tools by such things. My main problem is the difference in elevation between tablesaw, outfeed and sander. It makes it cramped for all but the smallest items.
My first thought was to build an elevated mobile base to bring the disc table level with the others but, that rapidly got complex and costly materials-wise. I was also getting so involved in "making a base" that I had veered far afield from the problem I was trying to solve. I stepped back, had a cup of coffee and thought about it. I had already built structural reinforcement into the cabinet to take the place of the solid front panel I removed when I built in the drawers.
I have a Rockler mobile base kit on my edge sander and it is designed to have the lift-wheel-pedal thingy move from one base to another. I simply sized a piece of hardwood, ran bolts through it, the metal cabinet and the internal supporting structure and viola. Now its just a step of the foot and she rolls right out.