3D Print a 3D model

Introduction

3D printing has become a common tool for manufacturing skeletons-, parts- or mechanisms for projects of all difficulties. If you know how to make 3D models in CAD or already have a model you need to print, 3D printing is a quick and cheap way of making a prototype.

In this guide, you will learn how to make a 3D printed model from an STL file. Note that this guide will not teach you how to draw in a CAD (computer-aided drawing) program. If you do not have a model already, you can download the "Benchy" 3D model here.

Repairing the model

The first step before printing the actual model is making sure that there are no errors in the STL file itself when it was converted from a CAD program. Most 3D print brands have a repair tool built-in in their slicer software. In PrusaSlicer you can right-click the model and select 'Fix through the Netfabb' which will then fix the mesh of the model. If you are at DTU Skylab or DTU Fablab you will most likely be using Cura, which will have the repair tool under extensions -> Mest Tools -> Fix simple holes/Fix model normals.

When converting a 3D model to an STL file, the model is converted into thousands of tiny triangles. Depending on the complexity of the model there are many different ways of misplacing or misaligning these triangles. The repair fixes these potential errors in the file.

If you don't have access to an STL repair tool, you can do it online using this link.

Convert STL To G-Code in Slicer software

The next step is to convert the file from an STL file to a G-code. G-code is a file with code that CAM (computer-aided machining) machines read to know what to do. To do this, the slicer program that accompanies your brand of 3D printer is used. DTU Skylab and DTU Fablab use Cura which is Ultimakers software. In the slicer, you can change settings such as support, infill, the thickness of layers, and much more. If this is your first-time 3D printing don't worry. The only thing you need to check is that infill is set to 20% (which is a good standard for most projects), support is set to none, and that the correct filament is chosen (check what filament is on the spool on the printer). The remaining settings can be left at default.

The slicer is also used to orient your model the way you want it. On top of this, you are not restricted to only print one model at a time. You can print multiple models at a time, as long as they fit on the print plate.

Once the configuration of the model is complete, insert a USB stick or SD card (depending on what the 3D printer uses) in the computer press the 'Slice now' button. Save to your USB/SD card and remove it.

Printing your 3D model

Insert your USB/SD card into the printer and print the model. Always stay around until the printer has printed the first couple of layers, to make sure that the print is turning out as intended. Nothing is worse than printing for multiple hours, only to come back to a big blop of filament on the plate. This is not only a waste of material but also a big waste of time. Should you notice that the print is not sticking to the bed, warping, etc. stop the print immediately and try again. If the same problem happens again, watch the troubleshooting section. Once the print is started you can monitor the remaining duration of the print as well as other info like heat, material, etc. depending on the brand. If you printed the attached Benchy model, the finished print should look something like this:

When the print is finished you can remove the print from the printbed. Remember to clean up after yourself once you are done with printing!

Troubleshooting

When 3D printing a lot of issues can occur. This can be either problem with getting the 3D printer to print the model properly, but issues with the model not turning out as expected are also common. simplify3d.com made a great troubleshooting guide that you can follow to figure out what the problem with your print is.