3D Printer -- Slicing

Once you have a 3D file, which is probably formatted as a *.stl file, you need to convert that file to *.gcode. This is a file that contains the sequence and instructions for how to move the stepper motors and extrude filament in way that is going to recreate your model. This is called "slicing" the model because each cross-section is treated one at a time. This step is not about designing the model, but more about planning for a tangible recreation of the model. This means that there are a few crucial things to consider.

Note: Be aware that the default unit of measurement native to the printer is the millimeter. If your file is calibrated to a different unit, be mindful about the actual size of your model file before printing it. It's possible that the conversion is handled automatically, but make a note of the size of your preview before you print.

Layering

Detail

The first option to look for is a control for the detail of the print. In the picture on the left, the character's fingers and facial features are visible, while on the right they are not. You can typically control the thickness of layers between about 0.05 mm (ulta-detail) to 0.35 mm (draft). If you decrease the layer size, your print may take a lot more time to complete.

Support

The second option to look for is a control for the addition of supporting material. In the picture on the left, the character's arm, sword, and cape are all "overhanging" -- meaning that there is an empty space below them. The additive process of 3D printing works best if you are printing each layer on solid material, which might be the build plate or a previous layer of filament. If any part of your model contains sharp overhangs, think about what is below those parts of the model. For example, a tree should be printed with supports from the build plate, because the lowest branches have nothing underneath them. A tree atop a mountain needs support everywhere.

To cut down on the amount of waste material, it may also be beneficial to use tree supports.

Infill

The third option to look for is a control for the interior of an enclosed part of the model. For example, you can build up walls for a room, but then the ceiling may be overhanging a large empty space. This is similar to the problem of supports, but you can specify a certain percentage of space to fill with material to allow enclosing layers to be supported. As a general rule: a cube needs infill, a pyramid does not need infill, and a sphere might need infill (depending on how large it is). The infill setting can also be used to add weight or rigidity, such as the difference between a table tennis ball and a golf ball. The default is 20%.