Rapid Network

• To decrease product development time (time compression technology)
• To minimise engineering changes
• To increase effective communication between engineers, product designers and marketing departments
• To extend the product life cycle

By letting the design department, manufacturing/production engineering and marketing departments see the model at an early stage allows costly errors to be eliminated. Any mistakes can be rectified before expensive tooling has been made for full production whilst the models at this stage are relatively inexpensive.

The word Rapid is relative as some models can take only a few hours to build whereas others may take several days. The time taken to build is dependent on the size, complexity and the technique being used.

The standard file format that is used between the CAD software and the rapid prototyping machines is the STL file format. Although for colour models such as those produced on the Z Corporation machines the VRML format is used, as there is no colour information in the STL file format. Both formats create an approximation of the shape of a component or assembly by using triangular facets. The smaller the triangles the smoother the surface, however, there is a point where there will be no further improvement because of the limitations of the technology. In order to see how the rapid prototype machines will see your model you need to turn off smooth shading in the 3D CAD software.

There are a variety of methods that can be used to deposit the material and which one is best for your project will depend on what you want from your models. They are:

• Stereolithography (SLA)
• Selective Layer Sintering (SLS)
• 3D Printing (3DP)
• Fused Deposition modelling (FDM)

All of these techniques require a second material that is known as the support material, which allows tapered surfaces and overhangs to be produced as the component is 'grown'. These come in a variety of forms that can be powder, liquid, wax or even the model material that has to be cleaned or removed from the model afterwards. Some machines generate the support structure for you so you have no control over where it goes, whereas other machines you have to manually generate the support material using specialist software.

Some of the other advantages to Rapid manufacture are:

• Low material waste
• Speed
• Complex Geometries
• Energy Efficiency

Rapid Manufacturing is widely regarded by experts as the next stage for Rapid Prototyping technologies.