Used some leftover steel tube and flat stock, plus a set of HD casters from Amazon, to weld up a mobile base for my woodworking planer. The factory mobile bases are $150 and up for objects weighing 500+ lbs, but they’re adjustable, so they tend to sag no matter how much I tighten them up. So out came my welder, and I had this base knocked out in a few hours for less than $40. Doesn’t sag - so far!