Rapid Prototyping Overview

What is rapid prototyping?

Today it is very important to guide a new product from concept to market quickly and inexpensively. Rapid prototyping technology aids this process. Rapid prototyping automates the making of a prototype. It builds a prototype part from a three-dimensional (3-D) CAD model.

Other terms used for rapid prototyping:

  • 3D Printing
  • Additive¬†manufacturing
  • Free-form fabrication

Why rapid prototyping?

To get a new product inexpensively to the market, you have to do it quickly. One way to gain some time is to shorten the design process. A prototype is indispensable. Conventional prototyping takes weeks or even months, depending on the product and the method used. Rapid prototyping is a method to make these prototypes much more quicker and also more cost-effective. Furthermore rapid prototyping is capable of making parts with very small internal cavity and complex geometrics. It is possible to see the real product in an early stage of the process of bringing a new product to the market.

How does rapid prototyping work?

Rapid prototyping was introduced in 1987. This technology is an additive process. An additive process builds an object by joining particles or layers of raw material. Other conventional processes are subtractive and compressive. Materials used for the additive process are photopolymers, thermoplastics, metal powders, and ceramic powders.

Stereolithography, which was one of the first rapid prototyping technologies, is a method that uses photopolymer in a vat. A laser generates an ultraviolet beam that solidifies focused surface areas of the photopolymer. The process begins with the vat filled with the photopolymer liquid. The operator loads a three dimensional CAD solid model file into the system. The control unit slices the model and supports into a series of cross sections from 0.004 to 0.020 inches thick. The computer-controlled optical scanning system directs and focuses the laser beam so that it solidifies a two -dimensional cross section on the surface of the photopolymer. The product turns to cover the solid polymer with another layer of the liquid. This process continues, building the part from the bottom up, until the system completes the product.

There are many other rapid prototyping technologies such as selective laser sintering (SLS), fused deposition modeling (FDM), fused peposition modeling (FDM), etc.

Some examples

  • With the help of stereolithography a prototype was being made of a telescope for a radiostation. The prototype was made at a scale of 1:200. With this prototype it was possible to do some checks in the windtunnel. In this way the engineers could do some really important measurements. A conventional prototype would have taken months to build.
  • A jewelmaker can also use this method very well. The prototypes build by rapid prototyping were used to make molds. The expensive labourcosts went down because of the use of the cost-effective prototyping!
  • A computer manufacturer made a computer inside a pen, the really personal computer. They built the computer in a pen, but for better sales results they had to come up with more then one packaging. Rapid prototyping helped them to design these different packagxings in a very short time.