To calibrate the galvo in LightBurn, the core feature you need is the "9 Point Correction". It effectively corrects issues like inaccurate sizing and pattern distortion caused by lens changes or prolonged use.

Simply put, the process consists of three steps: Draw a rectangle → Engrave it → Enter the measurement data back into the software. Let's go through it step by step.

🔧 Preparation

First, prepare the following items:

Measuring Tool

A digital caliper or a steel ruler 

Marking Material

A material that can produce a clear mark (e.g., black cardstock, black metal business card, stainless steel plate, aluminum plate, sintered stone plate, etc.). 

Equipment Ready

Ensure the device is connected and the laser type and fiber type are correctly set.

🎯 Starting the 9-Point Correction

1.Open the Correction Wizard

In the LightBurn top menu bar, click Laser Tools → Calibrate Galvo Lens → 9 Point Correction (Easy) to open the wizard.

2.Set Field Size and Test Area

LightBurn will automatically fill in the working area size of your current lens. Confirm this number is correct, then set the "Test Area Size" to 100% of the working area (e.g., if the working area is 100mm, enter 100mm). If your marking material is smaller than 100mm, adjust the test area size to about 95% of the material size (e.g., for 90x70mm material, enter 65x65mm).

· If your lens is f=100, set width/lens to 70mm

· If your lens is f=160, set width/lens to 110mm

· If your lens is f=210, set width/lens to 150mm

· If your lens is f=254, set width/lens to 175mm

· If your lens is f=290, set width/lens to 200mm

· If your lens is f=300, set width/lens to 220mm

3. Adjust Laser Output Settings

Set the power and speed appropriately to ensure the mark is clear and visible on the material. Make sure both red dots overlap before marking.

4. Mark Calibration Pattern

Place the material, then click Start to have the software mark a 9-point array test pattern.

5. Select Correct Orientation

Several small dragon patterns in different orientations may appear. Choose the one that exactly matches what you just marked.

📏 Measurement and Input

1.Click Next, Measure and Enter X/Y Axis Distances

Use the caliper to measure the horizontal (X-axis) and vertical (Y-axis) distances between adjacent marked points, and enter them into the pop-up window accordingly.

2. Apply and Finish

Click Done to save automatically.

3. Verification and Fine-Tuning

9-point correction alone is not enough. Go back to the drawing area, draw a 110mm square and engrave it, then measure the actual size.

4.Fine-Tune (If Needed)

If the 110mm square is not the correct size, manually adjust the Scale value under Galvo Configuration in Edit → Device Settings.

Example: Target is 110, Actual is 118.70

Repeat the process: draw another 110mm x 110mm rectangle, input the measured size for correction, and repeat until the measured size is close to the width (110). Acceptable range: 109.5–110.5mm.

5. Red Dot Preview Fine-Tuning (If Needed)

If there is a deviation between the marking position and the red dot preview, calibrate it in the Red Dot section of "Device Settings" by adjusting Offset X/Y and Scale X/Y.

❓ FAQ and Tips

Core Principle: Galvo lens distortion is inherent. The 9-point correction models and reverses the distortion by measuring reference points. After correction, you may still need to fine-tune these parameters in Device Settings → Galvo Configuration → Per Galvo Settings for further optimization:

· Scale: Corrects overall size enlargement or reduction.

· Bulge: Corrects center-area expansion due to lens distortion.

· Skew: Corrects tilt caused by non-parallel lens mounting.

· Trapezoid: Corrects trapezoidal distortion (one side larger) caused by the galvo head not being parallel to the worktable.

· Angle: Adjust if the entire marking result is rotated.

⚡️ Troubleshooting

· Mark is blurry: The laser is out of focus. Refocus until the line is as thin and clear as possible. 

· No mark at all: Check power and speed settings; try increasing power or lowering marking speed.

· Measurement note: The software asks for the distance between individual points. Measure those, not the entire outer frame length.

· Still inaccurate after correction: Double-check that the working area (Width) value is correct. If this base value is wrong, further corrections won't help.  

· If your lens is f=100, set width to 70mm  

· If your lens is f=160, set width to 110mm  

· If your lens is f=210, set width to 150mm  

· If your lens is f=254, set width to 175mm  

· If your lens is f=290, set width to 200mm  

· If your lens is f=300, set width to 220mm

💎 Creating Independent Device Configurations for Different Lenses

For the same machine, it is best to create a separate configuration file each time you change lenses:

1.You can take screenshots to save the correct parameters in case you misplace them.

2.For more details, refer to the official LightBurn website:

https://docs.lightburnsoftware.com/legacy/galvo/ConfigureGalvoSettings#max-speed-lightburn-17

3.If you encounter any issues during the actual operation, please contact our customer service promptly via the Email: service@em-smart.com