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G-code Basics

Understanding G-code helps you troubleshoot issues and customize Rayforge output.

High-Level Process​

Rayforge converts your designs into G-code through a multi-step process:

What Rayforge does:

  1. Analyzes your design - Extracts geometry from workpieces
  2. Applies operations - Determines cut/engrave paths
  3. Optimizes toolpaths - Reorders paths, minimizes travel
  4. Generates commands - Converts paths to G-code
  5. Injects hooks - Adds user-defined macros at specified points
  6. Writes file - Outputs complete G-code ready for machine

Simple Example​

Here's a basic G-code file structure showing a square cut:

G21 ;Set units to mm
G90 ;Absolute positioning
G54
T0
G0 X95.049 Y104.951 Z0.000
M4 S500
G1 X104.951 Y104.951 Z0.000 F3000
G1 X104.951 Y95.049 Z0.000 F3000
G1 X95.049 Y95.049 Z0.000 F3000
G1 X95.049 Y104.951 Z0.000 F3000
M5
G0 X95.000 Y105.000 Z0.000
M4 S500
G1 X95.000 Y95.000 Z0.000 F3000
G1 X105.000 Y95.000 Z0.000 F3000
G1 X105.000 Y105.000 Z0.000 F3000
G1 X95.000 Y105.000 Z0.000 F3000
M5
M5 ;Ensure laser is off
G0 X0 Y0 ;Return to origin

Key commands:

CommandDescription
G21Millimeters mode
G90Absolute positioning
G54Select work coordinate system 1
T0Select tool 0 (laser head)
G0Rapid move (laser off)
G1Cut move (laser on)
M4Laser on (dynamic power mode)
M5Laser off
S500Set laser power to 500 (50% for 0-1000 range)
F3000Set feed rate to 3000 mm/min