3D printing services have become increasingly popular in recent years as an easy, cost effective solution to create real parts from 3D CAD data. 3D printing is a term used to describe additive manufacturing technologies such as; Stereolithography (SLA), Selective Laser Sintering (SLS), Selective Laser Melting (SLM) and Fused Deposition Modeling (FDM). These manufacturing technologies produce custom parts by accurately “printing” layer upon layer of material until a 3D form is created. Additive manufacturing technologies can quickly create tangible parts that allow individuals to touch, feel and assess their design.
How does 3D printing work?
Every 3D print 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 lovely new 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 however could be an issue for FDM or SLM.
What is ‘CAD’ and ‘STL’?
CAD (Computer Aided Design) STL (STereoLithography / Surface Tessellation Language) file. These files can either be acquired from the internet but in most cases if you are after a specifically designed model/item you will have to either design it up yourself OR get someone else to do it (Tech savy friend or Design company). There are many CAD software packages available ranging from simple/free to industrial Software along the lines of Solidworks/Rhino. For more information please see the design software write up on the Shapeways website here.
What materials / methods are there?
There are many forms of additive manufacture which all work in slightly different ways using different materials, but essentially they all follow the same principals. 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.
What software do I need?
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 AUT Lab needs STL files in order to print, how you go about designing is up to you. For more information on free software for purpose please visit this link and explore the strengths of each software package.
Can I make interrelating parts?
Yes you can make Interrelating parts (parts that clip, rotate 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.
How do I get my files printed?
There are 2 options;
1) Email your STL files through to the technician
2) Pop by the lab during drop-in hours with your STL files. (Monday-Friday. 1:30pm -3:00 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 (e.g. inverted normals) then you will have to fix these and return with a clean/modified file.
How much does it cost and how do I pay?
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 then you can be invoiced.
How long does it take?
SLS During mid semester (off peak) the lead time is approximately 3-4 days HOWEVER during the busy periods (peak) when assignments are due, it is recommended you give 7 days as there can be a large queue for printing.
SLM This is dependent on materials desired and is calculated on a job-by-job basis, this is due to the need to flush the machine for various material types.
MACHINE OFF PEAK PEAK
SLS 3-5 days 4-7 days
FDM 1-2 days 1-2 days
SLM Calculated on a job-by-job basis