Additive manufacturing actually means that a computer generated virtual design from 3D design software is translated into thin horizontal cross-sections. These layers are created one at a time to create a real physical model where the layers are joined together or fused automatically to create the final model. That's why everybody in the Media and industry refer to the process as 3D printing.
It is a ‘what you see is what you get’ process where the physical model is almost identical to the virtual model. This gives the technology a fundamental advantage over traditional techniques as it can create almost any geometric feature or shape.
Why would you use 3D Printing?
- 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 3d printed 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.
3D printing is the latest way of producing not only rapid prototypes, but also rapid tooling, rapid jigs and fixture, also real production parts under certain circumstances. Parts can be 3D printed in 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 3D Printing machines will see your model you need to turn off smooth shading in the 3D CAD software.
There are a variety of methods under the 3D Printing heading In the professional machine category they are:-
- 3D Printing UV cured Acrylic, Projet and Objet
- 3D Printing using powder based material. Z Corp ( 3D Systems )
- Fused Deposition modelling (FDM) Stratasys
- Digital Light Processing (DLP)
- Stereo lithography (SLA)
- Selective Layer Sintering (SLS)
All of these can be used to deposit the additive material, however which one is best for your project will depend on geometry and what you want from your models. This is not an exhaustive list, further reading can be found at:-