Circular silicone molds were made for spincasting. The molds are spun in a small machine while resin is poured in the center. This method can help alleviate problems with airbubbles.

These are the molds for most of the smaller parts in the Petaminx. This mold has 30 parts, and it had to be run 30 times, plus extras for rejects and parts used to make assembly jigs later.