21-01-2016, 11:48 AM
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.Using a specialized software, a 3-D CAD model is cut into very thin layers or cross-sections. 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. The advantages of this process is clear: development of physical models can be accomplished in significantly less time as compared to the machining process. Some other applications of these technologies include development of models and tooling. Additionally, in the medical field, the convergence of medical imaging, CAD, and RP has made it possible to quickly develop medical models.
The term rapid prototyping (RP) refers to a class of technologies that can automatically construct physical models from Computer-Aided Design (CAD) data. These "three dimensional printers" allow designers to quickly create tangible prototypes of their designs, rather than just two-dimensional pictures. Such models have numerous uses. They make excellent visual aids for communicating ideas with co-workers or customers. In addition, prototypes can be used for design testing. For example, an aerospace engineer might mount a model airfoil in a wind tunnel to measure lift and drag forces. Designers have always utilized prototypes; RP allows them to be made faster and less expensively.In addition to prototypes, RP techniques can also be used to make tooling (referred to as rapid tooling) and even production-quality parts (rapid manufacturing.