Introduction to G-code

G-code is a motion control language used by a variety of computer-controlled equipment. CNC Mills, Routers, Lathes, 3D Printers, and a host of other industrial automation equipment use G-code to define how the machine moves. Being able to read G-code can help you understand why your build goes wrong, or to clean up the code that comes out of a CAM post-processor.

This class will be a “guided tour” of G-code, as implemented in the open source LiunxCNC motion control application. We won’t be going into great depth or cover the more esoteric aspect of G-code, but will introduce the highlights and more commonly used instructions. It should give you the basics you need to make sense of G-code programs and the effect they have on the behavior of a CNC machine. Even though we will be looking at LinuxCNC specifically, most of the information will apply to systems running GRBL and other G-code driven motion controllers.

The topics we will cover in this class include:

– basic G-code formatting and syntax, including line numbers and comments

– “modal” versus “non-modal” codes and common modal groups

– overview of commonly used modal and non-modal codes

While it is not required for the class, students may find it useful to have a working installation of LinuxCNC or Machinekit set up with the AXIS simulation configuration. A simulator is absolutely essential for testing code before trying it out on any actual CNC machine. I will be using Machinekit installed on a Raspberry Pi 3 and configured for simulation to demonstrate code behavior in this class.

Dates & Access:

Wednesdays; 2/3/21 – 2/10/21. All participants will receive a link to a live Zoom session prior to the start of the class.

Instructor: Brian Trimmer