Finding Something To Print

Model Sources

If you aren’t sure what you want to print, there are many websites where folks have created models that you can print yourself. Some such websites are:

• https://www.thingiverse.com/
• https://www.printables.com/
• https://cults3d.com/
  

The file that you download will typically be in the STL format (e.g., in a file called "mymodel.stl"). An STL file can be visualized as a series of triangles in 3D space, some of which share vertices. By defining enough of these triangles, we can form a 3D object:

Model "Gotchas"

Because of how 3D printers works, some models are difficult or impossible to print. There are ways to mitigate these issues, but for now, we recommend finding a model that is simple to print.

3D printers deposit very thin layers of plastic, line by line, on top of one another:

Filament, which is a long string of plastic, is fed into a hot nozzle, which moves around the print surface while slowly squeezing filament through. Many single lines of extruded plastic form a single layer of a print. Once the layer is complete, the nozzle moves up a fraction of a millimeter, and begins depositing more plastic on top of the previous layer.

This means that there are some parts which do not print very well. Please note: these are contrived examples, and often you can fix issues like these by simply re-orienting the part! The first two, for instance, could be printed sideways.

In particular, you’ll want to look out for:

1. Areas printed in mid air. Notice how the downward-facing spike has nowhere to start -- the nozzle would just extrude plastic into a blob on the build surface!
   

2. Large, steep overhangs. These aren’t quite as bad as printing in mid-air, but since only a small part of the next layer will be on top of the previous layer, these parts can sag and may fail entirely.
   
   
   

3. Parts with only a small area in contact with the build plate. These are likely to become detached from the force of the nozzle during the print.