13-12-2012, 05:22 PM
Rapid Prototyping Systems
Rapid Prototyping Systems.ppt (Size: 599 KB / Downloads: 25)
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
Conversion to STL Format:
To establish consistency, the STL (stereolithography, the first RP technique) format has been adopted as the standard of the rapid prototyping industry.
The second step, therefore, is to convert the CAD file into STL format. This format represents a three-dimensional surface as an assembly of planar triangles
Slice the STL File:
In the third step, a pre-processing program prepares the STL file to be built.
The pre-processing software slices the STL model into a number of layers from 0.01 mm to 0.7 mm thick, depending on the build technique.
The program may also generate an auxiliary structure to support the model during the build. Supports are useful for delicate features such as overhangs, internal cavities, and thin-walled sections.
STL files use planar elements, they cannot represent curved surfaces exactly. Increasing the number of triangles improves the approximation
Stereolithography
Patented in 1986, stereolithography started the rapid prototyping revolution. The technique builds three-dimensional models from liquid photosensitive polymers that solidify when exposed to ultraviolet light.