SimpleSumo Tyre Mold

I didn't have any flexible filament so I whisked up this mold so that I could cast the tire in silicon sealant.

Just coat the inside of the mold in Vaseline to stop the silicon sticking, put a good bead of silicone around the SimpleSumo's wheel part, set the wheel on the pedestal, so the pedestal goes inside the wheel to hold it in place, then squish the outside shells into place and wipe of the excess. Put some rubber bands around it and leave it to dry.