By Dr Kieran Meaney, UNE Discovery Voyager

For many people, 3D printing is a fantastic, almost science fiction type of futuristic technology hidden out of reach in engineering labs and TV prop studios.

But what if it wasn’t? What if it was available to you, right now?

3D printing is becoming increasingly accessible to the everyday person, with some hobby printers retailing for as little as $300. High school tech workshops, public libraries and maker spaces also commonly host a 3D printer or two where students or the public can use them. So how do they work, and what are they capable of?

The most common type of 3D printer that you will come across are FDM, or Fused Deposition Modelling printers. These printers hold a spool of plastic filament which feeds into a heated print head. The print head melts the plastic and then moves around to draw out layers, which build up to make your object. Every printer has a slightly different build volume, but some of the larger ones can produce objects up to 30cm x 30cm x 40cm, or in other words big enough to print out a costume helmet in one go. A full-sized helmet would likely need multiple days to print, however smaller objects or figurines, something similar in size to a Lego person for example, might only take an hour or less.

Filament 3D printers have four essential components:

• The extruder – Imagine a tiny hot glue gun filled with plastic. The extruder is the pen that draws out each layer of the print, building it up into the finished model.
• The build plate – A perfectly flat and level foundation is essential to every print.
• The motors – The motors control the left and right, forward and back, and up and down (X,Y,Z) motion of the build plate and extruder.
• Onboard computer – The brain that tells everything what to do.

3D printers can make just about anything you can think of. Here are a few examples from my own adventures in the 3D printing world.

Models of just about every video game character and associated props can be downloaded online. Engineering wonders such as these articulated finger extensions are always fun at parties. Keeping secrets safe is easy work when you can print your own combination safe. You can even 3D print photos! The possibilities are limited only by your imagination and creativity.

From Cyperspace to 3D Model

How do we make our model a reality from a digital file on the computer?

First things first, where do you even get a 3D model? There are many models that can be downloaded online, or you can design something yourself. The design process can be a very in depth process, so we won’t go into detail on that here. You can check out programs such as Tinkercad, Fusion360, or Blender 3D if you want to have a go at this. If you just want to download something, check out Thingiverse or Cults 3D. For now, let’s assume we already have a model that we want to print.

It’s important to know that a 3D printer works by printing layers of plastic that eventually build up to produce the full 3D model. So the digital model must also be sliced into thin, horizontal layers, and this requires slicer software. There are many different slicer programs, some are designed for specific printers and others are more general use, but they all do the same thing – digitally slice your 3D model into layers between 0.1-0.3mm thick for printing. As an example, I’ll demonstrate with a model of a Paracyclotosaurus fossil from UNE Discovery Voyager’s Rocking Through Time show.

Images of the 3D model of fossil/sliced model

In the slicer program, you will have to choose a range of settings that will affect the speed and quality of your print. This will be different for each printer and printed model, but some of the common settings you will have to think about are:

Temperature: Depending on the type of plastic you use, and even the brand of that plastic, you will need a specific printing temperature. Many printers also have a heated print bed to help the print stick.

Layer height: Thicker layers will mean your print will finish sooner, but it will have lower resolution and more obvious layer lines. Thinner layers give high quality prints but can take up to 3 times longer.

Supports: If your model has overhanging parts you will need support structures to hold up the molten plastic as each layer is drawn out. These are usually automatically generated in the slicer, but can be created manually to make them easier to remove from the finished print.

Print speed: If the print head moves too fast it can shudder, creating small imperfections or misaligned layers. Slower speeds mean higher quality but can test your patience.

Infill: in your slicer software you can create internal structures to improve the strength and quality of your print. Decide on the infill pattern and density that works best for the purpose of the print. This can have a big effect on the amount of filament used and time taken in the print.

There are hundreds of blogs and articles online that go in depth about the pros and cons of almost every setting imaginable, and the same settings could even lead to different outcomes on different models of printer. If you’re thinking of buying your own, be sure to read and watch a lot of reviews before choosing one to get to know your machine. If you’re using a publicly available one, be sure to chat to the technician about how to get the most out of your print.

Preparing the Printer

All of the hard work is done in the slicer software. When the settings are confirmed, we save the file and ‘send’ it to the printer. When it comes to setting up the hardware of the printer, the first thing to do is make sure the print bed is level. With layers only 0.2mm thick, if one side of the print bed is slightly out it could lead to trouble with the print not sticking down properly and detaching halfway through the print. The process for levelling will be different for every printer, and some advanced models will even self-level. Next, we load up the filament which is usually as simple as heating up the print head and inserting the end of the filament. Then we load up the sliced print file and press go. The printer does all the work from here.

Be sure to manage your expectations here, 3D printing does take a long time. If you’re building a model 10cm high, and all of your layers are 0.2 mm then you’re looking at 500 layers that need to be drawn out with enough time in between for the plastic to cool down and solidify enough to support the next layer without deforming.

So how can you give 3D printing a try? Thanks for asking!  The Armidale CoLab project, a collaboration between UNE Discovery, Armidale City Public School, Armidale Regional Council and Settlement Services Australia has got 3D printers for you to learn!