How to Calculate and Set Kerf Compensation on Your XTool S1 in XTool Studio

When laser cutting with the XTool S1, the laser beam burns away a small amount of material as it cuts. This is called kerf — the width of material removed during the cut. Just like a saw blade has thickness, the laser removes material, and this can affect the final dimensions of your parts.

If you’re making tight-fitting joints, press-fit assemblies, or parts that need to match pieces made on a 3D printer or CNC, ignoring kerf can lead to loose or overly tight fits. Learning how to measure and compensate for kerf in XTool Studio is one of the best ways to improve accuracy and get professional results.

Why Kerf Matters in Laser Cutting

The laser doesn’t cut with zero width. Even though the beam is small (typically 0.1–0.3 mm depending on settings and material), it vaporizes material on both sides of the cut line. This means:

• An outside cut makes your part slightly smaller than designed.
• An inside cut (like a hole) makes the hole slightly larger than designed.

This difference becomes critical when parts need to fit together precisely. Without compensation, a “perfect” 50 mm × 50 mm box might actually measure 49.7 mm, causing loose joints or assembly issues.

Kerf varies by material (plywood, acrylic, MDF, leather), thickness, cutting settings (power, speed, passes), focus, and air assist. That’s why you should measure it for important projects.

How to Measure Kerf Accurately

The most straightforward and reliable method uses a simple test cut and a digital caliper.

Step-by-Step Kerf Test

1. Prepare your material — Use the exact material and cutting settings you plan for your final project.
2. Design a test square — Create a 100 mm × 100 mm square (or larger if your caliper allows). Make sure it’s set to “Cut.”
3. Cut the square — Run the job on your XTool S1.
4. Measure carefully:
   • Measure the outer dimensions of the cut-out square (the part).
   • Measure the inner dimensions of the hole left in the base material (the cut-out).
5. Calculate kerf:
   • For each axis (X and Y):
     Difference = Inner hole size – Outer part size
     This difference equals twice the kerf (material removed from both sides).
   • Kerf width = Difference ÷ 2

Example:

• Designed size: 100.00 mm
• Measured part: 99.65 mm
• Measured hole: 100.35 mm
• Difference = 100.35 – 99.65 = 0.70 mm
• Kerf = 0.70 ÷ 2 = 0.35 mm

Repeat the test 2–3 times and average the results for better accuracy. Always measure multiple points on each side in case of slight variations.

Setting Kerf Compensation in XTool Studio

XTool Studio has a built-in Kerf Offset setting that automatically adjusts your cuts.

How to Apply It:

1. Select the objects you want to cut.
2. In the right-hand settings panel, find Kerf Offset (under cutting parameters).
3. Enter the value:
   • Use half the measured kerf as your base number.
   • Positive value (+0.18 mm): For outside cuts (makes the part larger).
   • Negative value (-0.18 mm): For inside cuts/holes (makes the hole smaller).

The software moves the cut path outward (positive) or inward (negative) without changing how the design looks on your screen.

After applying the value, run another test cut. Your parts should now measure much closer to the designed dimensions.

Pro tip: The compensation range in XTool Studio is -1.00 mm to +1.00 mm. Start conservative and fine-tune as needed.

When and How Often to Measure Kerf

• Every time you change material or thickness.
• When you significantly change power, speed, or number of passes.
• After major maintenance (lens cleaning, focus adjustments).
• For high-precision projects (boxes, mechanisms, multi-part assemblies).

Many makers create a small “kerf test file” they reuse with different materials and save the results in a spreadsheet.

Common Issues and Troubleshooting

• Parts still not accurate? This could be mechanical — linear deviation on the X or Y axis of the S1. I’ll cover machine calibration in a future post.
• Inconsistent results? Check focus, dirty lens, or material flatness.
• Joints too tight/loose? Adjust in small increments of 0.05 mm and re-test.

Conclusion

Taking the time to measure and set kerf compensation is one of the simplest ways to level up the accuracy of your XTool S1 projects. Tight-fitting joints, professional-looking assemblies, and reliable repeatability become much easier once you dial this in.

The process takes only 10–15 minutes but saves hours of frustration later. Whether you’re building functional mechanisms, gifts, or products to sell, kerf compensation makes a noticeable difference.

Have you measured kerf for your machine yet? What value did you get for your favorite material? Drop your results and questions in the comments — I read them all!

SNAFU… but learning !