G-code is a common language to instruct computerized machines how to accomplish certain tasks. Depending on the machine, G-code instructions may tell it to turn on, heat up, move to specific positions, move up or down, or stop. 3D printers, CNC routers (often used to carve wood and other materials), and many other tools utilize G-code.
Luckily we don't have to write the G-code by hand! There are several options for software that will let us load in our 3D model and set various parameters. The software will then generate the G-code based on our input.
The Auraria Innovation Garage uses Cura Ultimaker Edition and Cura Lulzbot Edition. These programs cannot read G-code from other programs, so it's best to bring in a 3D model that has not already been converted to G-code.
In fact, most of the preparation of a model for 3D print will be done by the Innovation Garage staff. The information below is helpful to understand the 3D printing process but, in most cases, you do not need to worry about these settings until your file is being assessed in the Innovation Garage.
There are many options for slicer software, but they all have many features in common. One, all slicers need to be configured for the specific dimensions and properties of your 3D printer! This includes things like:
In addition, each individual print can benefit from specific settings. We'll cover these in the sections on this page.
Often you can find premade profiles that provide information about a specific printer to a specific software. But caveat emptor! Just because you found a file doesn't mean it's guaranteed to work. That's why, in the Innovation Garage, we recommend the use of the Cura Lulzbot Edition slicer software, which is backed by our 3D printers' producers and which we've heavily tested. If you have a print that you think Cura won't work for, talk to us.
Layer height is one of the most important settings in determining the final quality of a print. A 3D printer works by building up individual layers of plastic on top of one another. The thinner the layer height (smaller number), the finer the finished surface of the print. However, you can also think of these layers like staircase steps. A smaller layer height means each "step" is smaller, so the machine must print more individual layers in order to get to the final height of the object. This means a slower (and potentially more expensive) print.
Image modified from http://tobuya3dprinter.com/3d-printing-resolution-structural-strength
Rough guidelines for layer height
Depends how tiny! On most FDM machines, regardless of the number you put into your slicer program, you're limited by the resolution of the stepper motors for the Z-axis (height) control and the extruder. 0.10mm (100 microns) is a reasonable minimum for these printers.
SLS printers commonly print layers in the range of 6-25 micron, which is what makes them so much more precise than FDM printers.
A skirt is an outline that surrounds your part, but doesn't touch it. Skirts are usually 1-2 layers tall. They're useful to help prepare the extruder and ensure filament is flowing smoothly before your print begins. It can also help you detect any bed leveling errors or other issues.
A brim is a thin extension out from the bottom of your part, usually 1-2 layers thick. Unlike a skirt, it is completely attached to your model. Brims help with adhesion of a model to the bed. In particular, they can help stabilize very small parts or other areas where the model does not have much surface contact with the bed.
A raft is literally like a small bed of filament that is printed underneath your model. Rafts are primarily used to help with adhesion of your print to the bed and encourage more uniform cooling of the filament, especially when using ABS material.
All images in this section courtesy of "Rafts, Skirts, and Brims!", Simplify3D.