G-code is a standardized programming language used to control CNC machines, including 3D printers. It consists of a series of commands that tell the printer exactly how to move, what temperature to maintain, and how fast to operate. Each line of G-code contains a specific instruction that the printer's firmware interprets and executes.
The G-code file is generated by slicing software, which converts a 3D model into a series of layers and then into machine-readable instructions. Common G-code commands include G0 and G1 for movement (G0 for rapid positioning, G1 for controlled movement), M104 and M109 for temperature control, and M106 for fan control.
G-code files contain various types of information: movement commands that control the X, Y, and Z axes; extrusion commands that control the E axis (extruder); temperature settings for the hot end and heated bed; fan speeds; and other printer-specific parameters. The file also includes comments (lines starting with semicolons) that provide human-readable information about the print settings.
Understanding G-code can be valuable for troubleshooting print issues, optimizing print settings, or creating custom print sequences. While most users don't need to edit G-code directly, being able to read and interpret it can help identify problems like incorrect temperatures, speeds, or movement patterns.
Modern slicers generate G-code automatically, but advanced users can modify the output to add custom start/end sequences, implement specific printing techniques, or optimize for particular printer configurations. The ability to understand and modify G-code is an important skill for advanced 3D printing users.
