Laser Cutter Settings
Starting-point settings for the shop's OMTech AF2440-100 (100W CO2 glass tube, Ruida controller, LightBurn). Speeds are mm/s, power is %. These are starting points, not guarantees — tube age, alignment, lens condition, and material batch all shift the numbers. Always test on scrap first and check the test-cut pieces near the laser.
⚠️ Never cut these — no exceptions
- PVC / vinyl in any form — sheet PVC, sign vinyl, records, faux leather ("pleather"), vinyl-coated fabric. Releases chlorine gas that injures you and corrodes the machine. No exhaust system makes it safe.
- Polycarbonate / Lexan — absorbs the beam, catches fire, soots the optics. Easily confused with acrylic: identify sheet plastic before cutting.
- ABS — melts, flares, emits hydrogen cyanide. Includes 3D prints and most plastic project boxes.
- HDPE / polypropylene sheet — melts gooey, kerf seals behind the beam, catches fire.
- Any foam (styrofoam, foam-core, insulation) — the #1 cause of laser fires.
- Fiberglass, carbon-fiber panels, epoxy/resin anything — uncuttable composites, toxic resin fumes.
- Chrome-tanned or coated leather — chromium fumes. Veg-tan only (blue/gray flesh side or core = chrome-tan = no).
- Galvanized, plated, or painted metal — zinc fumes cause metal fume fever; chrome/cadmium plating and unknown paints release toxic or carcinogenic fumes. Mark bare metal with compound, or anodized aluminum, only.
- Anything else chlorinated — neoprene, chlorinated rubber, CPVC, cling film. Unsure whether a rubbery or flexible plastic contains chlorine? It's a no.
Can't positively identify a material? Don't cut it. No label and no SDS means no. Ask a tool owner.
Dialing in a new material
- Start from the closest entry here or a test-cut piece near the laser.
- Run LightBurn's material test grid (Laser Tools → Material Test) on scrap of the exact sheet you'll use. Focus first — an out-of-focus test is invalid.
- If in doubt: less power, more passes — except acrylic, which must cut in one pass (repeat passes remelt the edge).
- Pick the fastest / lowest-power square that fully cuts through, and save it to your LightBurn material library.
- Watch the machine the entire time. Acrylic and cardboard can flare; cardboard can hold glowing embers after the job ends.
Machine practice
- Air assist: high for cutting wood, MDF, leather, and cardboard; low for raster engraving (hard air smears smoke across the work) — except cardboard, where fire control wins: keep air high for everything on corrugated. Low air also for cutting acrylic — that's what gives flame-polished edges. Never cut with air fully off.
- Min vs Max power (Ruida): Max Power applies at full speed; Min Power applies at or below the controller's start speed (~10 mm/s). For slow thick-material cuts (≤10–15 mm/s), set Min = Max or the cut won't go through. For normal cuts and engraves, set Min a bit below Max — but not below ~10%, or corners won't fire at all.
- Thick wood/MDF (beyond ~6 mm): prefer 2–3 moderate passes over one slow scorching pass. Thick acrylic: never multi-pass at any thickness — go slower in a single pass. Focus 1/3 into the material for straighter edges on 6 mm+.
- Tube life: the shop caps cut layers at ~70% power. A healthy, aligned 100W does not need 90% for 6 mm wood — needing it means dirty lens, bad focus, weak air assist, or misalignment. Ask before running anything above 70%.
- Kerf / press-fits: start with a 0.15 mm kerf offset (0.075 mm per side) for 3 mm ply or acrylic and calibrate with a test cut — kerf varies with lens, focus, and even X vs Y direction.
Full reference table
shop log tested on this machine · corroborated multiple independent 80–100W sources agree · scaled converted from similar machines · estimated extrapolated — test extra carefully
Data compiled July 2026 from OMTech, LightBurn documentation and forums, tube manufacturer specs (RECI), makerspace references, and this shop's own test logs, normalized to a 100W tube. Corrections welcome — tell a tool owner or open a PR on the website repo.