Cutting Acrylic on the xTool M1 Ultra: A 7-Step Walkthrough from a Quality Inspector’s Perspective

Who This Is For

If you’ve just unboxed an xTool M1 Ultra and are staring at a sheet of acrylic, wondering if you’ll end up with a clean cut or a melted mess, this guide is for you. I’m a quality compliance manager—I review products before they ship to customers. My job is about consistency and specifications. So, when I started using the M1 Ultra for small production runs (roughly 200 orders annually), I had to figure out the process that actually works, not the one that looks good in a marketing video.

This isn't a deep dive into laser physics. It’s a checklist. Seven steps. Do them in order, and you’ll get a reliable cut on acrylic. Skip one, and you’ll probably learn why the hard way (I have).

Step 1: Confirm Your Material Is Cast, Not Extruded

This is the first thing I check, and it’s where most beginners mess up. The xTool M1 Ultra uses a diode laser. It can cut acrylic, but only cast acrylic. If you try to cut extruded acrylic, you’ll get a cloudy, uneven edge, and the material may crack. The difference isn’t obvious from the packaging—both can look clear.

Here’s my test: I look for the manufacturer's label. If it says “cast,” you’re good. If it says “extruded” or nothing at all, I don’t use it for laser cutting. I’ve rejected a whole batch (about 50 sheets) of material because the vendor claimed it was “laser compatible” but it was extruded (ugh, that was a $300 mistake).

Quick check point: Cast acrylic is also known as “cell cast” acrylic.

Step 2: Set Your Exhaust System for Correct Airflow

Acrylic cut with a laser produces fumes. It smells bad and can be harmful if you don’t have proper ventilation. The M1 Ultra has a small exhaust port. You must connect it to an exhaust system. Don’t just open a window.

I use the xTool external exhaust fan (or a similar inline fan). The key spec here is static pressure. For a short run (under 10 feet of duct with one 90-degree bend), a standard inline fan works. If your duct is longer or has more bends, you need a fan with higher static pressure.

Per OSHA guidelines (and common sense), ensure your exhaust is venting outside. Recirculating the air through a filter (like a standard HEPA) is not adequate for laser fumes.

What to Check Before Pressing Start

• Is the exhaust fan running? (Listen for it)
• Is the airflow directed away from your workspace? (Don't vent into a hallway)
• Is your duct connection sealed? (A leak reduces suction)

Step 3: Use a Honeycomb Workbed—Not a Blade or Flat Plate

We cut acrylic on the M1 Ultra with the laser, not the blade. The “blade” function is for scoring or cutting thin materials like paper or leather. For acrylic, use the laser module.

The workbed should be the honeycomb panel. Why? Acrylic melts, and if the molten material touches a solid surface, it will fuse. The honeycomb allows the heat to dissipate and the residue to fall through. I once tried using the standard flat panel (out of laziness) and spent an hour cleaning melted acrylic off the grid.

If I remember correctly, the honeycomb panel is included in the M1 Ultra box (maybe the standard one, let me check—yes, the “standard” one is included).

Step 4: Set Laser Power and Speed—Start Low

This is where my quality inspector instincts kick in. Don't use the maximum power setting from the start. The M1 Ultra has a fixed laser module (which is 10W or 20W, depending on your model). The software has presets. Use the “Acrylic (Cut)” preset as a starting point.

For a 3mm cast acrylic, a typical starting point is:
Power: 80%
Speed: 5mm/s
Passes: 2

But test first. Cut a small test shape (a circle or square) in a corner of your material. Look at the result:

• If the edge is clear and clean, you’re good.
• If the edge is cloudy or has a white residue, your speed is too slow (or power is too high).
• If the cut doesn't go through after two passes, increase power to 90% or reduce speed to 3mm/s.

The numbers said to use 90% power. My gut said start lower. I went with my gut, and I’m glad I did. The first test cut was perfect at 80% (unfortunately, the next material was slightly thicker and required 90%).

Step 5: Focus the Laser—Use the Ruler

The M1 Ultra has a manual focus system. You can either use the auto-focus sensor or the included focus ruler. I recommend the ruler. The auto-focus sensor is okay, but it can be thrown off by material thickness or reflection. The ruler is more reliable.

Place the ruler on the material surface. The laser module touches the ruler. Tighten the screw. Done. The distance from the lens to the material is fixed.

In our Q1 2024 quality audit, I noticed that 7% of our test cuts had variation in edge quality because the autofocus had drifted. We specified the ruler method in our standard operating procedure after that.

Step 6: Monitor the First Cut—Don't Walk Away

This feels obvious, but I’ve done it. You press start, hear the motor, and think “I’ll check my email.” Don’t. Stay and watch the first 30 seconds of the cut. This is not a “set it and forget it” process.

Watch for:

• Flame: If you see a flame, the laser is too hot. Stop immediately. Check your material and power settings.
• Material shifting: If the acrylic moves during the cut, the result will be off.
• Smoke: Thin smoke is normal. Thick, dark smoke indicates burning (too much power).

I had a project once where I walked away for 2 minutes, and the material caught fire. That cost me a $50 sheet of acrylic and a replacement fan filter (fumes, ugh).

Step 7: Post-Cut Cleaning

After the cut, the edges of the acrylic will have a fine dust or slight residue. Don't brush it off with your fingers (acrylic dust is sharp). Use compressed air or a soft brush. For the laser exhaust fan, clean the filter every 5-10 hours of use.

One thing I’ve learned: the residue can cloud the edges. A quick pass with a soft cloth and some soapy water will clear it up. Don’t use alcohol or acetone—they can craze (crack) the acrylic.

Common Mistakes and Notes

• Don't cut reflective materials. Mirrored acrylic can reflect the laser back into the module, damaging it. The M1 Ultra is not for mirrored acrylic.
• Thickness limit. For the M1 Ultra's 10W module, practical cutting limit is around 3-4mm acrylic. For the 20W module, it can go to 6-8mm. Either way, expect multiple passes.
• No fire extinguisher? Get one. Seriously. I keep a small CO2 extinguisher nearby (used it once, thankfully not for a major fire).

This process works for me. If I’m cutting a high-volume run (say, 50 parts), I’ll run a full test sheet first (unfortunately, that’s lost time, but it’s better than ruining the whole batch). The key is consistency—every cut should look the same, and this checklist gets you there.