As this manufacturing process grows in popularity, the technologies being developed evolve rapidly as well. Machining is a subtractive process, beginning with a solid piece of stock. The machinist must carefully remove material until the desired geometry is achieved. For complex part geometries, this is an exhaustive, time consuming, and expensive process.
Some parts are even too complex to be machined.
Rapid Prototyping is a method in which the part is created by a layer-additive process. Then, depending on the specific method used, the RP machine constructs the part layer by layer until a solid replica of the CAD model is generated. Material selection is also method specific. Some other applications of these technologies include development of molds and toolings. Additionally, in the medical field, the convergence of medical imaging, CAD, and RP has made it possible to quickly develop medical models.