Mold for casting PUR wheel

thingiverse

This is a mold for casting a compact wheel using a two component PUR resin. For my case, I am casting the PUR track around an existing steel wheel. The final diameter is 284mm, the steel wheel is 100mm wide, while the track is around 90mm wide. I used a PUR resin with a hardness of 90 Shore, i.e. pretty hard. The final wheel should withstand a couple of tons of load. The mold consists of a lower part and an upper lid, plus three vents/pours. The lower part has two splits along the side to make releasing the mold easier. Note that for the resin I used, the pot life is short (5 minutes) while the resin takes 7 days to cure properly. I used plenty of form wax, which is quite visible in the final product.