Sculpfun SF-A9 40W Settings for Acrylic (PMMA)

Cutting Settings

How to Set Up Acrylic (PMMA) on the Sculpfun SF-A9 40W

1. 1Secure your acrylic (pmma) flat on the work bed using clamps, magnets, or a honeycomb pin set to prevent movement during the job.
2. 2Set your focus distance accurately — use the auto-focus probe if your machine has one, or measure manually with the focus gauge.
3. 3Important: Diode lasers can only cut dark or colored acrylic. Clear and transparent acrylic will not absorb the 445nm wavelength and the beam will pass straight through.
4. 4Enable air assist if available. A steady stream of air at the cut point removes debris, reduces charring, and helps prevent flare-ups.
5. 5Enter the speed, power, and pass count from the settings table above into LightBurn. The table lists both mm/min and mm/s — LightBurn defaults to mm/s, so use the mm/s value unless you have switched units. Use the “Cut” or “Engrave” layer settings panel.
6. 6Run a small test cut or engrave on a scrap piece of acrylic (pmma) before committing to your final project piece. Adjust power up or down by 5–10% based on results.

What to Expect When Lasering Acrylic (PMMA)

Diode lasers produce a frosted, matte edge finish on dark acrylic rather than the flame-polished look that CO2 lasers achieve. Engraving creates a lighter frosted mark on the surface. Results are best on black, dark blue, or dark red acrylic. Processing speed will be slower compared to CO2 machines. With 40W on tap, this machine cuts thick stock fast — often in a single pass — which limits heat buildup and keeps edges cleaner than slower low-power machines. The trade-off is that fine engraving needs the power dialed well down to avoid over-burning.

Common Mistakes to Avoid

• ✗Running at full power on the first attempt — always start with a test piece at the recommended settings and adjust incrementally. Going straight to maximum power risks burning through the material or causing fire.
• ✗Running at full power out of habit — a 40W diode usually needs far less power than expected for engraving and thin cuts, and too much melts or burns the material.
• ✗Trying to cut clear or transparent acrylic with a diode laser — the 445nm wavelength passes directly through clear acrylic without being absorbed. Only dark or opaque colored acrylic works with diode lasers.
• ✗Not removing the protective masking film before engraving — while masking helps during cutting, it must be removed for engraving to get clear results.

Tips for Acrylic (PMMA) on Laser Machines

• ✓CO2 lasers produce flame-polished edges on acrylic automatically.
• ✓Diode lasers cannot cut clear acrylic -- use dark or opaque colors only.
• ✓Leave the protective paper on while cutting to prevent surface marks.
• ✓Reduce speed for thicker sheets to ensure a full clean cut.
• ✓For engraving, use high speed and moderate power to get a frosted white finish.

Frequently Asked Questions

Other Materials for Sculpfun SF-A9 40W

Acrylic (PMMA) Settings for Other Machines