Prepare for your lab session

3D printing describes additive manufacturing technologies like stereolithography (SLA), selective laser sintering (SLS), selective laser melting (SLM) and fused deposition modeling (FDM).

Your 3D item needs to print from a CAD (computer aided design) file, generally in STL format. The printer software then slices this digital model into thousands of wafer thin slices. These slices are then sent to the printer. Material is then laid down in the exact cross sections of the slices, one on top of the other until you are left with your product.

This layer-by-layer manufacturing process allows for the direct fabrication of complex parts that could be cost-prohibitive, if not impossible, to produce through traditional manufacturing processes. For example, interior features, undercuts and negative draft are not an issue for SLS fabrication but could be an issue for FDM or SLM.

We will need your model file sent to us in a STL format.

CAD (computer aided design) packages with STL outputs, and pre-designed STL (stereolithography / surface tessellation language) files can be sourced from the internet but in most cases if you are after a specifically designed model or item you will have to either design it yourself or get someone else to do it. There are many CAD software packages available ranging from simple or free to industrial software like Solidworks or Rhino.

You can check out some of the 3D printing design options here

There are many forms of additive manufacture which all work in slightly different ways using different materials, but essentially they all follow the same principles. Each different method has its advantages and drawbacks, whether it be better surface finish, stronger model for working prototypes or full colour models for display. At AUT we have SLS, SLM, and Multi-Jet print services.

Your objective with your design will directly influence what software package you will use. For example, designing an organic form with random flowing forms will require different software than an engineer/ product designer who is designing a robot with specific rudimentary measurements and requirements. In the end the lab needs STL files in order to print, but how you go about designing is up to you.

You can make Interrelating parts (parts that clip, rotate, or move within other parts). When designing parts that interrelate there will be some considerations that needs to be taken into account and these will differ for each material/machine and your design requirements. Some of the processes will even allow you to design assemblies that are built as one and function/move post production.

There are 2 options for getting your files printed:

1. Email your STL files through to the technician
2. Pop by the lab during drop-in hours with your STL files (Monday to Friday, 1.30pm  to 3 pm)

If you bring them to the lab then the technician can look over your file, discuss what it is that you are after and possibly offer some suggestions if alterations are needed. It may also be the case that the files need to be fixed. If the files have large problems (for example, inverted normals) then you will have to fix these and return with a clean/modified file

On receiving your STL file you will be given a quote for your part. You can then pay on pick up at the lab using Eftpos. If you have an account with AUT we can invoice you.

SLS

During mid semester (off peak) the lead time is approximately 3-4 days. However, during the busy periods (peak) when assignments are due, we recommend you give 7 days as there can be a large queue for printing.

SLM

Timeframes depend on desired materials and are calculated on a job-by-job basis, because we need to flush the machine for various material types.

Machine      Off peak             Peak
SLS                  3-5 days                4-7 days
SLM                Calculated on a job-by-job basis