To pour silicone for the second part and get it to separately nicely, [Eric] uses sprues made out of resin rods that were ... one way to make a mold, especially for casting in metal.

The molds were designed in CAD prior ... cast in place consisting of threaded rods, and conduits for various electrical connections. After casting, [John] has spent much time measuring and truing ...

Rapid prototyping uses three-dimensional (3D) computer aided design to quickly fabricate a part or, alternatively, a sand mold for casting a part from metal. Currently there are many limitations with ...