What printers are available?
There are currently three 3D printers available through the UDS and ITS Research:
We will also provide some assistance to staff and students in using the software applications required to produce 3D objects suitable for printing.
What about software?
Any 3D modeling package that produces STL files, or a format that can be converted to STL. Some freeware applications that are worth looking at include Blender and Trimble SketchUp (formerly Google SketchUp).
How does 3D Printing work?
Layer upon layer upon layer
Our 3D printers use rolls of plastic filament which is heated to melting and deposited on a surface, a process also known as fused deposition modelling. Each layer bonds to the previous layer and the precisely controlled print head moves back and forth in an X-Y plane. Meanwhile the build platform is lowered by a miniscule amount for each layer pass, which defines the vertical resolution. Even the most basic 3D printers can achieve 200 micron accuracy but high-end printers are capable of less than 50 microns, which provides a surface that is perfectly smooth to the touch.
The process for 3D printing involves producing a 3D digital object first. This may be designed in software or captured from an external source, such as a 3D scanner (see below). A 3D scanner is used to digitise a physical object, producing a 3D surface representation on computer. This model can then be manipulated in many ways. For example, an ancient urn might be digitally repaired and then 3D printed. Or an object such as the Parthenon could be scaled down to a size that fits neatly in your palm.
3D printed objects produced in materials such as plastic or ceramics can also be painted, however with some high-end printers, full colour surfaces can be produced. When combined with 3D scanning, which is capable of capturing surface colour as well as texture, it is possible to produce a full-colour replica of an object.
Many objects have surface structure that is sufficiently complex that support structure must be printed along with the object itself. Whenever the object includes overhangs such as a bridge, or the inside of a building, a low density support structure is printed to maintain the structural shape. This material is removed when the job is complete, often by simply snapping it off by hand. This allows for extremely complex shapes, including having one object completely inside another. Some structures, such as proteins, require lots of support structure and this can be very difficult to remove. Printing the support in a different colour makes it easier to identify and therefore remove, but it is also possible with multi-head printers, to produce the support in a dissolvable material. In this case, once the job is complete, the printed object is immersed in liquid (water or caustic soda depending on the material) and it simply washes away, leaving only the object. Some high-end printers can also use wax for support structure, which is simply melted away after. Inkjet and laser sintering printers are able to use the powdered print material as support, which can also dusted, blown or washed away and reused for the next job.