How do I check if my laser beam is misaligned?
Updated:
Short answer
Misalignment shows up as quality that differs by direction or position on the table, not as a single obvious fault: cuts fine on one axis but rough on the other, or good near the centre and worse toward the edges. A burn-paper test at two points on the beam path finds it faster than guessing from the cut alone.
Signs of a misaligned beam
| Symptom | Likely cause | First action |
|---|---|---|
| Edge quality differs between X and Y direction cuts. | Beam not centred through the final bending mirror or nozzle. | Run the burn-paper or tape test at the last mirror and at the nozzle; compare spot position at both. |
| Quality good near the origin, worse at the far corners of the table. | Beam path drifts off-axis as the gantry travels, common after a collision or cable-chain wear. | Check alignment at multiple table positions, not just one spot — a single-point check misses this pattern. |
| Sudden quality drop after a service call or optics swap. | A replaced mirror or lens seated slightly off from the original. | Re-run the full alignment procedure after any optics work, not just a spot check. |
| Power reading normal but the cut looks underpowered. | Beam clipping on the nozzle or an aperture, losing effective power without a fault code. | Check for scorch marks or clipping at the nozzle entrance — a classic sign of an off-centre beam. |
Alignment and calibration procedures for your machine — inside the app. Open SBM Laser Help →
Or take it with you:
A basic alignment check
- Use burn paper or alignment tape at a fixed point near the laser source and mark the spot.
- Move to a second point further down the beam path — the last mirror before the head — and mark again.
- The marks should be concentric and centred; an off-centre second mark means the path has drifted between the two points.
- Repeat at a few table positions if the machine has a moving gantry — alignment can drift with travel, not just with time.
Related questions
- Is beam alignment something an operator should do, or only a service technician?
- Basic checks — burn paper, visual centring — are operator-level. Adjusting mirrors to correct a misalignment usually needs a trained technician; get it wrong and you can damage optics.
- How often does a well-maintained machine need alignment checked?
- Most manufacturers recommend checking after any collision, optics replacement or transport, plus a periodic check on the hour-based maintenance schedule — not as a routine daily task.
- Can software calibration fix a physically misaligned beam?
- No — software offsets compensate position, not beam angle or focus quality. A genuinely misaligned beam needs physical correction at the mirrors.