UNSW Making

3D Printing with FDM Printers

Essential tutorials and information to start working with FDM 3D printing and thermoplastics materials in the UNSW Makerspace Network

The following module will take you through the Material Extrusion 3D Printing process with plastics. You will learn about the FDM-Plastics machines available in the UNSW Makerspace Network, the Slicing Process to be able to print your 3D model, post-processing your printed parts and more!

What is FDM Printing?

What is FDM Printing?

FDM or Fused Deposition Modelling is the process of extruding a molten material through a nozzle following a defined toolpath. This process adds material layer after layer in specific places to create a tri-dimensional physical part.

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Types of Extrusion Systems


Filament Extruders

The most commonly used and versatile type of extruder that utilises spools of thermoplastic filament that are fed into the printer.

Pellet Extruder

Plastic Pellet Extruders

Similar to the filament extruders but using thermoplastic pellets or granules that are fed into a hopper before being melted and fed into the printer.


Paste Extruders

Sometimes left in it's own category as it doesn't use thermoplastics but rather any 'paste' material that can be extruded.

Learn more about paste extruders here in our clay 3D printing learning module!

FDM Printing at UNSW

Types of FDM Printers at UNSW

Ultimaker 3/3+

More Info

Ultimaker 2+ Connect

More Info

Ultimaker s5

More Info

Prusa i3 MK3

More Info

Creality CR-10

More Info

Delta Wasp 4070

More Info


Common Filaments for FDM Printing



+ Excellent visual quality

+ Easy to print with

+ Can be post-processed easily

- Low impact strength



+ Food Safe*

+ Good strength

+ Easy to print with

+ Recyclable



+ Water soluble

- Difficult to print with



+ Very flexible

- Difficult to print accurately



+ High strength

+ Excellent wear and chemical resistance

- High fume emissions

- Absorbs Moisture



+ Good impact resistance

+ Good heat resistance

- Warps upon cooling

- Difficult to print



+ Good strength

+ Good temperature resistance

- More susceptible to warping

- Requires printer to be enclosed

Design Considerations

FDM design considerations

Considerations when Printing

Take note of some of the things that may affect your parts when printing as you may need to make adjustments to your design to incorporate these features.

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Part Strength

For functional parts, it is important to consider the application and the direction of the loads. For example, FDM parts are much more likely to delaminate and fracture when placed in tension in the Z direction compared to the XY directions (up to 4-5 times difference tensile strength).

Source: 3D Hubs
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Because FDM printing nozzles are circular, corners and edges have a radius equal to the nozzle size. This means that these features are never perfectly square.

For sharp edges and corners, the first layers of a print are especially important. With each print layer, the nozzle compresses the print material down to improve adhesion. For the initial print layer, this creates a flare often called an “elephant's foot”. Protruding outside the specified dimensions, this flare can impact the ability to assemble FDM parts.

Source: 3D Hubs
Orientation of parts.jpg

Orientation of Parts

The best way to avoid support for holes is by changing the print orientation. Removal of support in horizontal-axis holes can often be difficult, but rotating the build direction 90° eliminates the need for support. For components with multiple holes in different directions, prioritize blind holes, followed by holes with smallest to largest diameters and then the criticality of hole size.

Source: 3D Hubs

STL Files & 3D Printing

An STL is the industry standard file type for 3D printing. It uses a series of triangles to represent the surfaces of a solid model. All modern CAD software will allow you to export their native file format into STL. The 3D model is then converted into machine language (G-code) through a process called “slicing” and is ready to print.

STL 1.jpg

Guide to STL Files

STL 2.jpg

Troubleshoot Common File Errors

Preparing files for FDM Printing

What is Cura?

Cura is an open-source, free slicing software used to prepare files for 3D printing. Cura will open and read your 3D CAD drawn model (in the form of a .STL or .OBJ), slice it up into lots of layers and convert those layers to lines of code that become the instructions for the 3D printers to follow!

First step...download Cura!

Download Cura

Get Familiar with Cura

Learn to slice your models and get your design ready for printing by following along the Cura fundamentals learn page!

Cura Fundamentals
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Other Resources

interlocking joints.jpg

Design Interlocking Joints for 3D Printing

snap fit joints.jpg

Design Snap Fit Joints for 3D Printing

Related Badges

Categories: Digital Fabrication