You start a job on the xTool P3 and, instead of starting to cut, you hear the hit: the air nozzle drags or collides with the material. Sometimes it moves it and ruins the piece; sometimes it just grazes it, and that graze leaves marks that are harder to remove than the hit itself. It’s almost never the machine: it’s the distance measurement, the actual height of the material, or a piece that has lifted halfway through cutting.
This guide adapts xTool’s P3 nozzle collision support documentation into Spanish, with the specific cases we have encountered in production.
Where the hit comes from
The P3 measures the distance to the material before processing and lowers the head to the working height. If that measurement is wrong—or if the material changes height during the job—the head lowers more than it should and the nozzle hits the piece. The causes fall into four groups:
- Incorrect measurement: the measurement point falls on a slot, a hole in the design, or leftover material.
- The material fools the sensor: transparent surfaces, uneven heights, or curved pieces.
- The material moves during the job: cutouts that come loose and lift, or boards that warp.
- The sensor is uncalibrated: the least frequent cause, and there is a way to check it before opening a ticket.
In our workshop, the two recurring cases are the third: small pieces that lift after being cut and warped plywood. Both have workshop solutions and neither requires support.
Make sure the measurement is taken where it should be
First of all, check where the machine is measuring:
- The origin area must be clean. The reference point for the measurement is in the slots of the slats in the origin area. If there is a cutout, compacted sawdust, or a piece of fallen material there, the measurement will be distorted. Remove it before starting anything.
- The material must not cover those slots. If the piece is so wide that it covers the reference, the measurement will fail or give a large deviation. In that case, switch to manual mode and enter the distance manually.
- The measurement point cannot fall into a gap. If it measures right over a cutout or hole in the design, the reading is invalid. Measure over a solid part, or stick a piece of masking tape over the gap, measure on top, and then remove it.
Materials that fool the sensor
Transparent materials. The P3 does not measure transparent materials well: the sensor passes through the top layer and measures against the background, so the reading is much lower than the actual value and the head lowers too much. The usual fix is the same: masking tape on the surface before measuring. If you work with acrylic, this is not optional.
Uneven heights. The elevator platform mode assumes all material is the same height. If you put pieces with more than 3 mm difference between them, the higher ones take the hit. Level them or process them in separate batches.
Curved pieces. For non-flat objects, select the curved material mode in xTool Studio instead of measuring as if it were a board.
Clearance before measuring. Check by eye that the material surface is not higher than the lower part of the nozzle. If it is, lower the platform with the wheel until leaving at least 4 mm of clearance before starting the measurement.
Pieces that lift when cutting
This is the most common for us, and it’s tricky because the measurement was correct: the problem appears halfway through the job. When a small cut finishes cutting, it falls, tilts, and stands on edge sticking out above the plane. The head, which is already at its height, knocks it over on the next pass.
What works:
- Bridges (tabs) in the design. The fundamental solution: leave micro-connections that hold the piece until the end of the job and break them by hand afterward. It’s the first thing to try on small pieces.
- Honeycomb panel instead of slats when the job involves many small cuts. The honeycomb [xTool EU] prevents the piece from slipping and standing on edge.
- Extra support slats under the cutting area, to reduce the gap through which the piece can fall.
Our other case is warped plywood. A board that arches rises by several millimeters in the center or at the edges compared to where it was measured. Here what solves it is mechanical fastening: magnets or clamps at the corners, and if the board is very warped, measure at the highest area and not the lowest. A warped board also cuts unevenly, so holding it well fixes two problems at once.
The other damage from rubbing: the dirty nozzle stains
With very warped materials —especially plywood— you have to accept one thing: the nozzle rubbing against the surface is not a risk, it’s a fact. In the areas that are higher, the nozzle will brush against even if the measurement was correct and even if there is never a hard hit.
And here appears damage no one warns about. After long engraving or cutting jobs, the nozzle accumulates sticky residue: condensed smoke, resin, material remnants. When that dirty nozzle brushes the high part of a warped board, it doesn’t scratch it: it stains it. Dark streaks remain, very similar to marker marks, and they are quite hard to remove afterward — especially on unfinished wood, where the residue soaks in.
So the real risk with warped material is twofold, not just one: the piece moving due to impact, and getting stained even though the machine hasn’t done anything “wrong.” What prevents this:
- Clean the nozzle frequently, especially before working on material you know isn’t flat. It takes a minute and saves you from ruining the piece.
- Flatten or firmly secure the board, not just rest it: the less the high area protrudes, the less surface contact there is.
- Mask with painter’s tape the areas you know are high. If there’s contact, the mark stays on the tape.
On rotary
With the rotary accessory, make sure the machine measures over the highest point of the cylinder’s surface. If it measures on the side of the piece, the reading is lower than the actual height of the top generatrix, and the nozzle hits as soon as the head passes the center.
Removing the nozzle on engraving-only jobs
If a job is engraving only on all its layers, you can remove the air nozzle assembly. You gain vertical clearance and completely eliminate the risk of damage. We do this regularly.
And here comes the real problem the manual doesn’t mention: mixed jobs. On a piece that has engraving layers followed by cutting, the nozzle must be installed for cutting. In practice, you don’t always remember to disable the cutting layer before starting engraving without the nozzle, and the job goes straight to cutting without it.
Ideally, there would be a setting that allows you to pause the job between engraving and cutting, install the nozzle, and resume. That same pause would also serve another common purpose: applying painter’s tape before cutting, once the engraving is done on the substrate — this way you protect the surface from cut splatter without the tape interfering with engraving. Currently, this doesn’t exist, so the routine is to split the job into two files: one for engraving and one for cutting. Less convenient, but it prevents damage.
(If you're interested in why the tape is applied before cutting, we explain it in more detail in the extra dots and splatter guide.)
Check if the sensor is miscalibrated
If you have ruled out everything above, it’s time to verify the sensor. In xTool Studio, select processing with the lift platform and launch the measurement on a flat material. Then measure by hand with a ruler the distance between the bottom of the laser module and the material surface, and check that it meets:
- Entered distance value (mm) = manually measured distance − 30 mm, with an acceptable tolerance of ±1.5 mm.
If it matches, the sensor is fine and the problem is operational: review the previous points again. If it doesn’t match, the measurement module is miscalibrated and that is a support issue: record a video of the measurement process and the collision, and have the serial number and exported work log ready. If the ticket gets stuck, it can be escalated via their Discord.
Frequently Asked Questions
Can I always work without the nozzle and forget about the problem?
No. In engraving yes, but in cutting the nozzle directs the assist air to the work point, and without it the edge will come out yellow or burnt. This is exactly the problem explained in the yellowing cut: without properly directed air, there is no clean cut.
I got dark streaks, like from a marker, without any hit. What is it?
It’s the dirty nozzle rubbing against the high spots of a warped material. The sticky residue it accumulates after long jobs transfers to the substrate and leaves those marks, which are quite hard to remove on unfinished wood. Clean the nozzle before working with material that isn’t flat, and mask with tape the areas you know are high.
The measurement comes out fine but the hit still happens, what should I check?
If the reading was correct at the start, the material has changed height during the work. That is: a piece that lifted when cut, or a board that warped from heat. Tabs, honeycomb, or mechanical clamping.
What about with acrylic or materials with transparent film?
Masking tape over the area where it will measure, always. The sensor measures through the transparent layer and gives a false height. This is the number one cause of hits on laminated materials.
How often should the distance sensor be recalibrated?
This is not periodic maintenance. Check it with the formula only if you have ruled out all other causes; if the result is within ±1.5 mm, there is nothing to adjust.
Written by Noemi and Javi, from Picasita. We have been using an xTool P3 [xTool EU] in production since October 2025; we are xTool affiliates. This guide adapts the brand's official documentation; the original is available in their support center. More tutorials and solutions.
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