To print a part for your project, you first need to create a 3D model.
Do I Need to 3D Print This?
Before diving into the process, the first question you should ask yourself is: “Do I need to 3D print this?“.
If your design is a basic shape like a box, or some flat structure, it might be more sustainable and cost-effective to create it using traditional methods (e.g. cutting wood, using cardboard). For any custom components, like holders or speficic features, you can then 3D print them separately and attach them to your main structure. This can also be a lot more sustainable than using plastic.
If your design includes complex geometries, or you need something very precise, 3D printing is probably the right option for you.
Planning Your Design
It is a good idea to start by sketching your design with pen and paper. Try to think of the dimensions, overall structure, and how all the parts will fit together. Your sketch does not have to be perfect, but it will help a lot with translating your concept into a 3D model.
Creating the 3D Model
To design your part digitally, Computer-Aided Design (CAD) software is highly recommended. CAD tools are optimised for creating precise, real-world objects with accurate dimensions, unlike more general 3D modelling tools like Blender.
For this course, there are two programs we recommend using:
- Tinkercad, an easy to use, browser-based CAD software. It uses shape-based modelling, which is ideal for beginners. We recommend this for most parts.
- Fusion 360 is professional-grade CAD software that is free to use for students. It is more complex, but more powerful than TinkerCAD. This is recommended only for really complicated designs.
Optimising Your Design
To ensure your design is efficient and practical, it is a good idea to keep the following in mind:
Make sure your measurements are accurate to ensure all your components fit together. Take time to double-check, especially for designs that involve interlocking parts.
Try to design your parts in such a way that they can be printed and assembled separately. By breaking your model into samller components, you can iterate more quickly. It allows for faster testing and adjustments without having to reprint the entier model. For example, if you are designing a holder for a specific component, printing it on its own ensures you can verify its fit and make any necessary modifcations before moving on to the rest of the design.
Minimise material usage. You can optimise the geometry of your design by using lightweight structures such as mesh patterns or cutouts where structural strength is not as important. Avoid adding unnecessary bulk that don’t contribute to the functionality of your part. This all reduces material usage and print time.
It is also important to keep in mind the inherent limitations of 3D printers. A 3D printer cannot print in mid-air, so parts with large overhangs, greater than 45 degrees, will require support structures. Designing your part to avoid supports where possible can save time and material. If supports are unavoidable, consider splitting the part into multiple sections that can be printed separately and assembled later. It also has a limit to how precise it can print your model (0.4mm for our printers).
Finally, remember that 3D printers build objects layer by layer, which creates a grain. This means that the part will be stronger in one direction than the other and may break more easily along the layer lines. Keep this in mind, especially when designing small, tall structures.
Exporting Your Model
Once you have finished your 3D model, the next step is to export it. The standard format is STL. This format represents the surface of your design as a mesh. The STL file can then be imported into the slicer software where you prepare it for printing. More information about the preparing your model for printing can be found here.