By using an STL file from a 3D CAD package (see Rapid Protyping elsewhere on this blog) a 3D model of a component or assembly may be constructed in a manner similar to a print-out from a conventional printer, but in 3D form, with successuive layers of a liquid, chemical powder or other thin material placed one on top of the other. It is essentially the creation of a 3D result from a large number of thin 2D laminated layers which are fused together.
It has the advantage of high accuracy to the concept design at low cost.
It is a time-consuming process (models generally take hours to produce) and the result may require some “finishing” using special materials to remove extra supporting structures that are required for the model’s construction. However, it enables the rapid prototyping process to be used to good effect (see the benefits of rapid protyping elsewhere on this weblog).
A transparent image of a typical 3D printer
3D printers currently available can produce finished surfaces made of various materials, although metal is generally difficult and expensive to use. If a printer can that utilise the required material cannot be found, the model can still be used to produce a mould or other final production tool for the actual production run. As a result 3D printers are useful modelling tools with a limited, but useful, range of capacities for production of real components.
One exciting development of 3D printers in recent years has been the development of printers that can reproduce their own parts when failures/malfunctions are detected.
3D model of an escalator step (top side showing construction lattice)