Profile: RP Prototype Limited specializes in prototyping and short run production. Our services include CNC machining, vacuum casting and silicone tooling. CNC machining or prototyping is a subtractive rapid prototyping service in that it takes a block of material and then the unwanted material is machined away to leave the finished part. The main advantages are that precision and repeatability, which can be achieved in a wide range of real production materials, fast lead times and relatively low cost compared to other processes such as 3D printing. Injection molding is manufacturing process for plastic part production where the plastic material is injected into a mold with high temperature and pressure. Small extruded plastic pellets are fed through a heated barrel where they are mixed and then injected into the mold that has a cavity in the shape of the parts to be produced.