Related Prototyping Technologies
The majority of rapid prototyping technologies currently available work
directly from three dimensional CAD files. There are many methods for
constructing the prototype, but they all rely on the identical strategy of
building the physical object from the bottom up as a compilation of very
thin cross sections stacked one on top of the other and fused together.
Each process begins by sectioning the CAD model into thin layers. Each
layer is then rendered in a suitable medium in a way that fuses the new
layer to the previous one The actual steps vary depending on the
technologies used, loosely categorized as follows:
The controlled exposure and solidification of light sensitive liquid
polymer resins.Stereo
Lithography and Solid
Ground Curing are two very
different techniques which both rely on the sensitivity of liquid
polymer resisns to specific frequencies of light.
The fusion or binding of powders using lasers or a
technology similiar to ink-jet printing. Three
Dimensional Printing, Direct
Shell Production Casting (DSPC), and Selective Laser
Sintering (SLS)use
a wide range of powders to prototypes as objects or ready to use molds.
The use of ink-jet technology to build objects by applying layers of
molten wax and/or thermo-plastics one on top of another (an analogy
would be making candles by dipping rather than using molds). These systems
tend to incorporate machine milling to ensure uniformity of layer
thickness or of built-up surfaces. Fused Deposition
Modeling (FDM) is very clear and strait forward; Topographic Shell
Fabrication (TSF) can produce very large prototypes; and
the Model
Maker 3D Plotting System is so conscientious in its reliance
on relatively benign wax and plastic that it can be used at home.
The laser-cutting and bonding of sheet material to compile the
model or prototype. Laminated
Object Manufacturing (LOM) produces
objects from any material material available in paper-thin sheets.
3/27/97