Why the xTool P3 scorches the plywood (and what really works)

Let’s start with the basics: the P3 cuts wood wonderfully. It’s what we do most with it and where it performs best. That said, we had the machine for a little over a month when the scorching of plywood stopped being a curiosity and became an issue to master. We mainly sell wooden pieces, and a piece with a blackened edge is not delivered.

It’s by far the number one complaint from owners of this machine. And after struggling with it for a few weeks, the conclusion is that most of the time it’s not the machine’s fault, nor the settings. It’s the wood’s fault.

What does work: our plywood parameters

Let’s start with what’s useful, which is what we would have liked to find in November. These are the settings we use to cut plywood daily:

With that, it cuts perfectly. Not sometimes: always, and on the first pass.

Now the honest part, which separates this from a brochure: getting completely clean cuts is difficult. It cuts well, goes through well, the piece comes out whole and to size. But the edge is marked. To deliver, we do one of two things: low-adhesion blue painter’s tape on the surface before cutting, or a light sanding afterward. For large batches, the tape pays off; for single pieces, sanding is faster.

If someone shows you a perfectly white plywood cut fresh out of the machine without protection or post-processing, ask them what kind of wood it is. That’s exactly where we’re headed.

The root cause that almost no one mentions: the glue

This is the part that was hardest for us to understand and the one that saves the most trouble.

Plywood is not wood: it’s a sandwich of thin sheets glued with adhesive. And that glue is what stands between your laser and a clean cut. The plywood you buy at a big DIY store is glued with adhesives designed for furniture, not for laser cutting. When the beam hits that layer, the glue does not vaporize cleanly: it drips burning and blocks the cut. The result is the scene everyone knows: the machine makes three passes, the piece still doesn’t come out, the edge is blackened, and there are spots where it simply hasn’t gone through.

The proof that the problem is the glue and not the power lies in the numbers circulating among owners: a 6 mm plywood labeled for laser cuts at about 40 mm/s, while one of the same size without that label requires slowing down to about 12 mm/s. Same thickness, same machine, same lens. The only difference is what’s between the sheets, and the result is more than triple the time.

Buy plywood specifically for laser, the kind with water-based glue. It’s more expensive per sheet but infinitely cheaper per finished piece. With that material and the machine preset, most of the "doesn’t cut" issues disappear.

How to distinguish good plywood from bad at a glance

And you don’t need to be an expert or rely only on the label: you can tell quite well by looking at the wood. Look at two things, the color of the outer faces and the appearance of the core at the edge:

• Laser-suitable plywood usually has light and uniform toned veneers, without marked dark grains, and a clean core, without gaps or thick, dark glue lines between layers.
• The DIY or craft type tends to show more irregular faces and, above all, darker and visible glue lines on the edge, as well as possible internal gaps. That dark glue is exactly what will give you trouble.

It’s a distinction that is widely documented: if you search for "laser-suitable plywood" you’ll find guides with photos comparing faces and cores, and once you get the eye for it, you can tell it in the store before buying. Ten seconds looking at the edge saves you a whole sheet and half an afternoon of frustration.

What xTool says, including an interesting admission

The official stance on yellowing is this:

A slight yellowing is inevitable due to the high-temperature process.

And it’s true. We are burning wood in a controlled way; expecting zero marking is expecting the process not to be what it is. They recommend wiping with a damp cloth afterward and working with wood that has a protective film, and both things work.

But there is a second official statement that is much juicier because it is a full admission about the air assist:

Due to its internal structure, the P3 has limitations in housing higher volume and power air pumps. Although its flow rate is significantly higher than the P2S, it can fall short compared to an external air compressor.

Translated: the integrated air of the P3 is better than that of the previous model, but worse than an external compressor, and they know it. And the air assist is precisely what carries away particles and gases from the cutting area before they settle on the edge. Less air, more marking.

We appreciate that they say it openly instead of hiding it. And it explains why, with difficult materials, you end up playing with speed and passes more than you'd like.

The hidden parameter: power in the corners

This deserves its own section because it solves a very specific and very annoying symptom: corners more burnt than straight sections.

The reason is mechanical. At a corner, the head has to brake, change direction, and accelerate again. During that braking, the laser keeps firing, but the head moves slower, so in those millimeters the wood receives much more energy per unit of travel. Hence the black spot at each vertex.

xTool solved it via firmware with a setting that lowers power in those transitions. In the software, it appears under the parameter "Cut", and by default it’s set to 9.5% of the processing power. You can set it to a specific value instead of leaving it at the default percentage.

If your straight lines come out fine but your corners come out burnt, that’s where to look. It’s the difference between blaming the machine and fixing it in thirty seconds.

Lowering power doesn’t eliminate the problem, it only reduces it

Everyone’s instinctive reaction, ours included, is to lower the power until it stops burning. It’s good to know how far that path goes, because it doesn’t go as far as you’d expect.

The data circulating among owners for 3 mm plywood is illustrative: at 10 mm/s with 40% power the scorching is reduced but doesn’t disappear. And look at the speed: 10 mm/s is very slow. You’re tripling or quadrupling the work time just to still have marks on the edge.

That’s the catch. Going slow with low power isn’t gentler: it’s having the beam on the same spot longer. Beyond a certain threshold, lowering power and speed at the same time worsens the result instead of improving it. That’s why we do the opposite — 90% power and 30-50 mm/s —: going in strong and coming out fast burns less than going in weak and lingering.

The score trick for thin materials

There is one case where it’s worth reconsidering the entire operation. With very thin materials — thick cardstock, technical paper — changing the operation from cut to score allows working at 400 mm/s instead of the 300 mm/s limit for cutting, and the result comes out with much less burnt edges.

It’s a software limit, not a hardware one, and taking advantage of it when the material allows is one of the most cost-effective optimizations there is.

The left-right asymmetry

A detail that appears in the forum frequently enough not to be an anecdote: the P3 does not deliver exactly the same power across the entire work surface.

The specific case circulating among owners is a 3 mm wood that cuts at 80% at 25 mm/s on the right side but needs to drop to 22 mm/s on the left. The software itself also warns that there’s less power in the upper left corner.

It’s the physics of a gantry laser: the beam travels a longer optical path to reach some areas than others. The practical thing is to know this and place critical pieces in the good zone, or adjust with a small margin if you’re filling the entire bed. If you’re calibrating parameters with a test in one corner and then producing on the opposite side, you’ll go crazy for no reason.

Our method when a new material arrives

After these weeks, this is what we do, in this order:

1. Ask about the glue before buying the sheet. If the supplier can’t tell you if it’s laser-compatible, assume it’s not.
2. Test grid in a corner of a scrap piece, varying power and speed. Ten minutes here saves a whole sheet.
3. Start fast and slow down. It’s easier to recover a piece that hasn’t cut all the way through than one that’s been scorched.
4. Masking tape if the visible surface matters.
5. Check the corner adjustment if the problem is concentrated at the vertices and not on the straight sections.

What we’ve learned in a little over a month

Plywood scorching is often read online as a machine defect, but it’s not. It’s the sum of three things: a material that almost no one buys correctly, an integrated air assist that the brand itself admits is inferior to an external compressor, and a corner adjustment that comes with a default value not everyone knows about.

With the right material and those settings, the P3 cuts plywood without question and at a speed that makes production viable. What it won’t give you is a perfect factory edge without any effort on your part. Tape or sandpaper: there’s no third option, and by now it’s part of our process as just another task.

If you just installed yours and are still struggling with smoke extraction, start there: we explain it in the article about the IF2 and the AP2 Max, and it’s more related to scorching than it seems — smoke that isn’t evacuated deposits on the cut.

Written by Noemi and Javi, from Picasita. We are affiliates of xTool and our workshop is a brand demonstration space; we bought our P3 on the day it was released. More about this blog and our relationship with xTool.