Won't the pressure from injection molding deform the mold if it is flexible enough to flex for the undercuts? Is there a psi limit for depending on the mold material used?

Quote Originally Posted by awerby View Post
For solid parts you don't need to use rotocasting (although it can help if the mold is likely to catch air in its recesses). For short-run injection molds, you can use steel-filled epoxy. For molds you're simply pouring resin into, you can use silicone or urethane rubbers, which will flex to release undercuts.

Andrew Werby
Juxtamorph.com