Longer Ray5 20W Acrylic Cutting: Settings, Tips, and Speeds
Cutting acrylic with a diode laser requires care — fumes are hazardous, and cut quality depends heavily on power and speed. The Ray5 20W handles 3mm cast acrylic reliably in one or two passes.
Safety First
Acrylic fumes are toxic. You need active fume extraction ducted outside. Never cut PVC — confirm material with a flame test (acrylic burns blue/yellow, PVC turns flame green).
Cast vs Extruded Acrylic
Cast acrylic (paper film): cuts cleanly with a flame-polished edge — the right choice. Extruded acrylic (clear plastic film): tends to melt and weld back. Avoid.
Recommended Settings (LightBurn)
| Thickness | Power | Speed | Passes | Air Assist |
|---|---|---|---|---|
| 2 mm | 100% | 8 mm/s | 1 | On |
| 3 mm | 100% | 5 mm/s | 1–2 | On |
| 4 mm | 100% | 4 mm/s | 2 | On |
| 5 mm | 100% | 3 mm/s | 2–3 | On |
| 6 mm | 100% | 2 mm/s | 3 | On |
Air assist is not optional — it clears combustion gases and dramatically improves edge quality.
Focus
Use the included spacer block for correct focal distance. For thick acrylic (4mm+), set focus at mid-material thickness for cleaner multi-pass cuts.
Cutting Technique
- Elevate acrylic off the bed with pins — laser reflects off the bed back into the cut
- Leave protective film on during cutting — reduces flashback marking on top
- Wait 30 seconds after cutting before moving — edge is still soft
Troubleshooting
Incomplete cut: Slow down or add a pass. Check air assist. Melted/welded: Extruded acrylic — switch to cast. Brown edges: Too slow, heat soaking. Increase speed and add passes. Top surface marks: Leave protective film on.