Precision plastic balls from .75″ to 10″ are molded with or without metal inserts, and other polyurethane plastic ball sizes can also be custom molded. Both the urethane and the insert are ...

These custom molded urethane battlebot wheels are a ... which were also machined but could easily have been 3D-printed. Polyurethane resin is poured in and adheres to the plastic hub better ...