Step 2Making the base
iImage Information

You need a plywood circle that fits inside the outer lip of the wheel. Mine needed to be 18". You could probably just draw a cicle and cut it out but I've never had real good luck cutting a smooth circle so I made a jig of sorts. I took the foot off of my jigsaw and drilled a hole in it on each side of the blade. Then I screwed a piece of wood to the foot at a 90 degree angle to the blade and made a hole in it for the blade to go through. Then reattached the foot to the saw. I measured 9" from the blade and drilled a hole just a hair bigger than a wood screw. With the saw blade sitting tight against the edge of the plywood put a screw through the jig and into the plywood. Now the saw will pivot around the screw as you cut a perfect circle without worrying about following a line. After cutting it out I sanded the edge to remove any splinters.
Paint the base flat black (pictures didn't turn out) so you don't see it when you look down through the wheel and let it dry overnight. I painted the top and the sides but left the bottom unpainted for several reasons. I was running out of paint because I didn't start with a full can, also it would make it hard to see marks you'll be making to align holes for the allthread and the casters. When was the last time you saw a piece of furniture that was painted on the bottom anyways?