Rapid Prototyping

Rapid Prototyping is the process of creating a three dimensional picture on a computer which in turn is used to create a three dimensional model. Rapid Prototyping is very useful because it produces full size three dimensional models in a very short time. This allows the designers to feel, touch, and look at the model during the entire design process. Having a model of the desired final product helps find problems much earlier in the design process. The methods of RPT employed by us are Stereolithography, Selective Laser Sintering, Fused Deposition Modeling. It requires a CAD model in STL format as the input for the RP machine.

Stereolithography takes a three dimensional CAD drawing of the product and makes a model of it. A low powered ultraviolet laser beam engraves a two dimensional cross section of the product onto a mass of photocurable resin. The beam causes the resin to harden, the resin is rotated, the laser then begins another cycle. Soon there is a three-dimensional model that formed from all the scans joining together. The material used is Epoxy Resin.

Selective Laser Sintering uses a laser to sinter a layer of powder. Sintering is heating something without melting it. The individual pieces of powder join to form one layer of the model. Once the entire cross section has been formed another layer of powder is laid on top and the entire process is repeated. The materials used are DuraForm PA (Nylon), DuraForm GF (Nylon GF), Laser Form ST – 100 (Stainless Steel)

Fused Deposition Modeling uses a three dimensional computer generated picture to create minute slices of an object. These slices are then formed, one at a time, by a robotics like extruder head. It is both fast and accurate. Fused Deposition Modeling, like many other rapid prototyping processes, reads STL file. The process of Fused Deposition Modeling can be done using Acrylontrile-Butadyne-Sytrene or ABS plastic P-400.

As its name suggests, the primary use of rapid prototyping is to quickly make prototypes for communication and testing purposes. Prototypes dramatically improve communication because most people, including engineers, find three-dimensional objects easier to understand than two-dimensional drawings. Such improved understanding leads to substantial cost and time savings.

Prototypes are also useful for testing a design, to see if it performs as desired or needs improvement. Engineers have always tested prototypes, but RP expands their capabilities.