How it works
Here we shed a bit more light on the dark art of printing in 3D
Depending on what you’re producing, and the amount you’re willing to spend on a 3D printer, there are a variety of ways that you can print a 3D model at home. Some techniques involve lasers cutting through material, some fire UV beams at resin, but the technique used in the majority of home 3D printers is called FDM (fused deposition modelling) – liquid plastic basically.
Simply put, FDM involves pushing heated filament (plastic, in most cases) through a tiny nozzle, building up thin layers, or ‘slices’, as it goes along. The more detail you want in your model, the longer it takes, as the printer needs to lay down more layers, which are measured in microns. In most cases the filament used for FDM printers is either PLA or ABS, which are categorised as thermoplastics; this means they can be easily be heated to a soft state, and then cooled to a solid. And you can buy these filaments on reels from companies such as colorFabb (colorfabb.com) and Fashberdashery (faberdashery.co.uk).
ABS requires a heated bed to print on to, otherwise it tends to curl, but it has a better strength and flexibility than PLA. However, PLA can provide more detail in prints, warps less, comes in funkier colours, and gives off less noticeable fumes. Also, it’s plant-based, whilst ABS is a petroleum-based plastic.
So there’s quite a lot to consider before you get started, but there’s one common element across all 3D printing: the model. You can create models in a CAD or 3D app (such as AutoCAD 360 or 3ds Max). And if you want to have a go at making 3D models without having to learn a pro app, Autodesk has an amazing suite of free, 3D tools available at 123dapp.com. But thousands of readymade models can also be found via online repositories such as Thingiverse, Shapeways, i.materialise, Sketchfab and YouMagine.
If you do choose to design your own model, you will need to ensure it’s exported as a 3D printer-friendly model format, which will either be an STL or an OBJ file (all the printers we’ve featured support these formats). But there’s one last thing you need to do.
Because 3D printers work in slightly different ways, and have their own idiosyncrasies, you need to convert your OBJ or STL file via an app called a ‘slicer’ (many printers come with their own, such as Ultimaker’s Cura app). What this app does is take your model, and – based on the parameters you set – create a file that transforms your model into a series of layers. This is called G-code. And G-code makes the magic happen!
FDM involves pushing heated fila ment through a tiny nozzle