So essentially the prototype and production processes may be one and the same. However, stereolithography can be used to create a plastic pattern rather than wood. Wood is much more durable and should be your first choice if changes aren t anticipated and volume production is imminent. Sand casting can be used for almost any kind of metal. For parts that will be die cast in volume production, two main prototyping processes are available.
Investment casting requires a master pattern, which is usually made by stereolithography.
A silicone rubber mold is made from the pattern, and then wax replicas of the master pattern are cast. The wax replicas are coated with plaster, the wax melted out, and molten metal is poured in under a vacuum to eliminate trapped air. The plaster shell is destroyed when removing the part, but the process of investing is fairly quick and even robotic in many facilities. Large die cast parts are often made by the plaster mold process. This process is similar to investment casting in that the mold is destroyed with each part made.