During daily operation of laser welding machines, many users may encounter problems that seem difficult to resolve, such as:
Welding sparks fluctuating in intensity;
Weld seams appearing higher on one side and lower on the other;
Welding wire suddenly failing to melt.
In fact, these issues usually originate from three key factors: optical lenses, focal length, and laser spot alignment. Let’s analyze them one by one.

1. Lens Contamination or Damage
Lenses are critical components in the laser transmission path, and any problem with them directly affects welding stability.
Typical Symptoms: soldadora laser starts normally, but over time the wire fails to melt properly, sparks weaken, or a large uncontrolled flame appears.
Possible Causes: The protective lens is contaminated by smoke and dust, or it has been damaged (burned) due to prolonged high-power exposure.
Solutions:
Regularly inspect lens surfaces for dust, oil stains, or spatter buildup.
For minor contamination, clean with specialized optical cleaning tools; if burn marks or damage are observed, replace the lens immediately.
Maintain a clean working environment to minimize dust and fumes.
2. Incorrect Focal Length Setting
Focal length determines how laser energy is concentrated on the workpiece surface. If misaligned, weld quality will decrease significantly.
Typical Symptoms: Weld seam appears scattered, unfocused, with insufficient penetration or uneven surface.
Possible Causes: The focal point is incorrectly set, preventing energy from being effectively delivered to the weld area.
Solutions:
Use a focal length test plate to observe the minimum spot diameter and ensure the focal point is aligned with the material surface or required depth.
Adjust the focal length according to material thickness and reference process parameters for accuracy.
3. Spot Misalignment or Red Light Deviation
Proper laser spot alignment is critical to weld seam formation and overall appearance.
Typical Symptoms: Weld seam is uneven, with one side higher than the other; the wire consistently sits on the edge of the red guiding light; weld seam deviates from the desired position.
Possible Causes:
Incorrect nozzle size selection;
Misaligned laser spot or red light deviation.
Solutions:
Confirm that the nozzle diameter matches the process requirements.
If correct, adjust the red guiding light to align the spot to the center.
Once aligned, the weld seam will be more uniform, aesthetically pleasing, and wire fusion will improve significantly.

ConclusionRoutine Maintenance and Recommendations
Regular Inspection and Maintenance: Core components such as lenses, nozzles, and fiber heads should be inspected weekly, with replacements made if any abnormalities are found.
Maintain Cleanliness: Avoid excessive dust and fumes in the work environment, and clean protective lenses regularly.
Prompt Troubleshooting: Most common issues are relatively simple to resolve. However, if the cause is unclear, contact the manufacturer’s technical support team to avoid further damage caused by improper handling.
Conclusion
The stability and appearance of welds in fiber laser welding equipment largely depend on three factors: clean lenses, accurate focal length, and correct spot alignment. By performing regular inspections and maintenance, most issues can be prevented or resolved quickly.
If you encounter persistent challenges or require process optimization guidance, please feel free to consult our technical team. Foster Laser is committed to providing professional, efficient solutions to ensure stable and reliable performance for your production needs.
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