Excellent question! Cutting 10mm (3/8") acrylic is a common task for signage, displays, and fabrication, and it's where CO2 lasers truly shine. Getting the settings right is key to achieving that perfect, flame-polished edge. Here are the best CO2 laser power and speed settings revealed, along with crucial tips for success.

The Short Answer (Starting Point)

For a 60W to 100W CO2 laser​ (the most common range for this application), a good starting point is:

• Power:​ 80-90% of Max Power
• Speed:​ 8-15 mm/s (0.3-0.6 in/s)
• Passes:​ 2-3 passes are strongly recommended.​ One-pass cuts often require excessive power, leading to melting, flare-ups, and poor edge quality.
• Air Assist:​ HIGH.​ A strong, focused air jet is non-negotiable. It keeps the cut clean, cools the edges, and prevents flames.

Important:​ These are starting parameters. You must​ test on a small piece of your specific acrylic, as results vary by machine brand, lens type, and acrylic composition (cast vs. extruded).

The Detailed Guide: By Laser Power & Type of Acrylic

The optimal settings depend heavily on your laser's wattage.

1. For a 60W-80W CO2 Laser​ (Desktop/Prosumer Models)

• Focus:​ Ensure perfect focus. Use a 2" lens for better depth of field on thick material.
• Technique:​ Multiple passes are essential.
  • First Pass:​ Power 85%, Speed 12-15 mm/s. This scores a deep, clean guide channel.
  • Second/Third Pass:​ Power 90%, Speed 8-10 mm/s. These passes complete the cut. The slower speed on the final pass helps polish the edge.
• Why it works:​ This method prevents overheating. Each pass removes material incrementally, allowing heat to dissipate and producing a cleaner edge than one high-power blast.

2. For a 100W-130W CO2 Laser​ (Industrial/Production Standard)

• This is the sweet spot​ for 10mm acrylic. It can often cut in 1-2 passes with excellent quality.
• Starting Settings:
  • Two-Pass Method:​ Power 75-80%, Speed 15-20 mm/s. Reliable and high-quality.
  • One-Pass Method (if necessary):​ Power 90%, Speed 6-10 mm/s. Monitor closely for excessive melting.​ Air assist must be at maximum.
• Advantage:​ The higher power allows for faster speeds or fewer passes, increasing throughput without sacrificing edge clarity.

3. For a 150W+ CO2 Laser​ (Heavy-Duty Industrial)

• Power is not the limiting factor; control is.
• Settings:​ Use lower power percentages​ (60-70%) at higher speeds​ (20-30 mm/s) to avoid vaporizing too much material and creating a wavy or melted edge. Often a single pass is sufficient.

Critical Factors Beyond Power & Speed

1. Cast vs. Extruded Acrylic:
   • CAST ACRYLIC (Recommended):​ Cuts cleaner, produces a superior flame-polished edge, and is less prone to melting. Use the settings above.
   • EXTRUDED ACRYLIC:​ More prone to melting and can produce a "stringy" or bubbled edge. Reduce power by 5-10%​ and ensure your air assist is strong. Test first!
2. Lens & Focus:
   • A clean, unscratched lens is vital.
   • A 2.0" or 2.5" focal length lens​ is better for 10mm material than a standard 1.5" lens. It provides a longer "depth of focus," keeping the beam tighter through the entire thickness for a perpendicular edge.
3. Air Assist:​ This cannot be overstated. A high-pressure air pump or compressor with a focused nozzle will:
   • Blow molten debris away.
   • Keep the cut path cool.
   • Prevent flame-ups (acrylic is flammable).
   • Result in a smoother, glossier edge.
4. Machine Calibration:​ Ensure your bed is level and your beam is aligned. An uneven bed will cause inconsistent cutting depth.

The "Perfect Cut" Checklist:

• ✅ Edge is Crystal Clear & Smooth:​ A true fire-polished finish straight from the laser.
• ✅ Minimal to No Melting/Rounding​ on the top edge.
• ✅ Vertical Kerf Walls:​ The cut is perpendicular, not V-shaped.
• ✅ Easy Part Removal:​ The piece drops out or lifts out with gentle pressure—no snapping or sticking.
• ✅ No Flames or Excessive Smoke:​ Controlled vaporization.

Troubleshooting:

• Edge is Frosted or Rough:​ Increase power slightly or slow down the final pass. Check lens cleanliness and focus.
• Top Edge is Melted/Rounded:​ Too much power or too slow speed. Increase speed, reduce power, or improve air assist.
• Cut Doesn't Go Through:​ Increase power, decrease speed, or add another pass. Check focus height.
• Yellowing/Burning on Edge:​ Too slow or poor air flow. Increase speed and max out air assist.
• Cut Starts Fine but Doesn't Finish Through:​ This is a classic sign of being out of focus. Re-focus or switch to a longer focal length lens.

Final Pro-Tip:​ Always perform a test grid​ on a scrap piece. Create a small grid of squares cutting at varying powers and speeds (e.g., 80%/10mm/s, 85%/8mm/s, etc.). This 10-minute test will save you hours of wasted material and give you the perfect, dialed-in setting for yourmachine and youracrylic. By following this guide, you'll master cutting 10mm acrylic, producing professional, ready-to-use parts with the stunning edges that make CO2 lasers the go-to choice for this material.