Start with the head manufacturer’s focus procedure
The correct focus reference depends on the cutting head, lens assembly and machine calibration. First check whether the machine provides an autofocus calibration, reference scale or approved focus target. Do not assume that a scale reading of zero is the true focus unless the maker’s procedure says so.
1. Use the built-in calibration or approved target
Follow the machine manual to set or verify the focus reference. Confirm the correct head model, lens configuration and calibration data before applying a value. If the calibration has drifted or cannot be completed, stop and have a trained operator or service technician investigate.
2. Make a controlled test cut
When the machine maker allows process testing, use a suitable coupon of the same material and thickness as the job. Start with the approved cutting chart, change only one permitted focus value at a time, and compare the cut-through, taper and edge quality. Record the settings and repeat the test to confirm the result.
3. Ask a qualified technician to measure the optical setup
A service technician can use the head maker’s specified alignment and measurement tools to check the optical path and focus calibration. This is appropriate when the beam path, optics or head has been serviced, or when normal calibration does not resolve the issue.
Laser safety
Do not direct an exposed laser beam at wood, paper or another improvised target to find the focus. Do not open the head or bypass interlocks. Follow the machine’s laser safety procedure and leave optical alignment to personnel trained for the exact equipment.
Photo suggestion
Show the approved focus target or a labeled test coupon inside the guarded machine, with the head model and material details recorded. Do not photograph an exposed beam or an improvised burn test.