CO2_LASER_101
ZERO-TO-FIRST-CUT ▸ THE FUNDAMENTALS OF CO₂ LASER CUTTING & ENGRAVING
> WHAT_IT_IS
A CO₂ laser uses a gas mixture (primarily carbon dioxide) excited by electrical discharge to produce a focused infrared beam at 10.6µm wavelength. This beam vaporizes or melts material along a programmed path. The laser head moves on a gantry (X/Y axes) controlled by software — typically LightBurn.
CO₂ lasers are the most versatile laser type for non-metal materials. They cut by vaporizing a narrow kerf (typically 0.1–0.3mm) through the material. They engrave by removing a thin surface layer to create contrast.
> LASER_CLASSES_&_SAFETY
CLASS 4 LASER — CRITICAL SAFETY
- ▸ Never operate with the enclosure open (if enclosed machine)
- ▸ CO₂ laser light is invisible (10.6µm IR) — you cannot see the beam
- ▸ Never look into the beam path. IR does not trigger blink reflex
- ▸ Keep fire extinguisher within arm's reach. Laser cutting IS fire management
- ▸ Never leave a running laser unattended — fires start in seconds
- ▸ Ensure proper ventilation — smoke and particulates are harmful
- ▸ Know your material BEFORE cutting (see NEVER CUT list below)
> NEVER_CUT_THESE
> WHAT_IT_CUTS
> HOW_IT_WORKS
- ▸ Design in vector software (Inkscape, Illustrator) or LightBurn directly.
- ▸ Export as SVG or AI. LightBurn also imports images for engraving (raster mode).
- ▸ Set power (% of max wattage) and speed (mm/s) based on material and thickness.
- ▸ Higher power = deeper cut. Slower speed = more energy per mm = deeper cut.
- ▸ Focus the lens — the focal distance determines the beam waist (smallest point).
- ▸ For cutting: use air assist (compressed air blown at the cut point) to reduce flame and improve edge quality.
- ▸ For engraving: lower power, higher speed. Raster mode scans back and forth like a printer.
- ▸ Test on scrap first. Material varies — even plywood from the same batch can behave differently.
> FOCUS_&_LENS
The lens focuses the beam to its smallest point (the beam waist). The distance from the lens to the material surface must be exactly the focal length — typically 50.8mm (2") for standard CO₂ lenses.
Focus gauge: Use the provided spacer block or focus probe. Place on material surface, adjust bed height until the nozzle just touches the gauge. This sets the focal distance precisely.
Thick materials: For materials thicker than the depth of focus (~5mm), you may need multiple passes or a longer focal length lens.