It is not normal for sparks to be deflected to one side during laser cutting, which usually indicates that the cutting process is asymmetric or unstable. This can affect the quality of the cut and, in severe cases, may damage the nozzle or lens. The following are the possible causes of the problem and the corresponding solutions, which can be systematically checked according to this list:
Main reasons and solutions
1. The beam and nozzle are not the same axis (the most common reason)
This is the most classic and primary troubleshooting problem. The laser beam must exit perpendicularly from the center of the nozzle.
- Performance: Sparks (slag) continue to bias to the fixed side.
- Reason:
- Incorrect installation or damage of nozzle (ablation, bumping of port).
- The optical elements (focusing mirror, protection mirror) in the focusing mirror module (cutting head) are contaminated or damaged, resulting in beam deflection.
- The collimating or focusing mirror mount is displaced.
- Solution:
- Do optical path correction (centering): This is the core operation. Use a clear plastic sheet (such as acrylic) to dot the underside of the nozzle and observe whether the ablation spot is in the center of the nozzle. If it is not centered, adjust the mirror behind the laser cavity (usually operated by professionals to adjust the M1 and M2 lenses).
- Check and replace the nozzle: make sure that the nozzle is of the correct type, free from damage and tightened in place.
- Clean or replace the lens: Check the protective lens and focusing lens for stains, water stains or burns. Note: Use special tools and cleaning fluid to clean the lens to avoid scratching the coating.
2. Auxiliary gas problem
- Performance: The spark is biased to the side where the gas pressure is low or the gas flow is not smooth.
- Reason:
- The nozzle is blocked (partially blocked), resulting in asymmetric gas outflow.
- The gas pipeline is bent or leaked, and the gas supply is uneven.
- Improper air pressure setting (too low or too high).
- Solution:
- Clean or replace the nozzle.
- Check the gas path to ensure that the pipeline is unblocked and the joints are fastened.
- Adjust the air pressure according to the material and thickness. Too low air pressure will not blow away the slag, too high may disturb the molten layer.
3. Improper setting of cutting parameters
- Performance: accompanied by rough section, hanging slag.
- Reason:
- Incorrect focus position: The focus is too deep or too shallow, resulting in non-concentration of energy and uneven melting.
- Power/speed mismatch: The power is too high or the speed is too slow, causing the material to melt excessively; the power is too low or the speed is too fast, causing the material to not cut through, and the slag is blown to one side.
- Solution:
- Recalibrate focus: perform a focus test to find the best focus position for the current material.
- Optimize cutting parameters: refer to the parameter table of the equipment manufacturer, and carry out small sample test, adjust the power, speed and frequency to the best combination.
4. Sheet or processing state problems
- Performance: appears when processing certain areas or specific plates.
- Reason:
- The surface of the plate is rusted, painted or uneven.
- The sheet is not clamped flat, there is a tilt or lift, resulting in a change in the cutting distance (nozzle height).
- Cutting directionality effects (e. g., speed changes cause heat build-up when cutting sharp corners).
- Solution:
- Clean the plate or choose a better quality material.
- Ensure that the plate is flat, check the machine table and fixture.
- For complex graphics, add micro-connections in the programming software or use the leapfrog function to optimize the cutting path.
5. Equipment mechanical/hardware problems
- Performance: may be accompanied by abnormal sound, cutting lines are not straight.
- Reason:
- Guide rails and gears are worn, resulting in unstable operation of the cutting head.
- The coupling is loose, creating a gap.
- Damage to the internal parts of the cutting head, such as the ceramic body, affects the airflow and beam.
- Solution:
- Contact the equipment supplier for mechanical inspection, maintenance and calibration.
Quick self-check flow chart
You can quickly locate the problem by following these steps:
Sparks to one side
↓
1. Check the nozzle → is it clean and in good condition? → No → cleaning/replacing
↓
Yes
2. Check the protective mirror → Is it clean and undamaged? → No → Cleaning/replacement
↓
Yes
3. Do nozzle alignment test → Is the beam centered? → No → Calibrate optical path
↓
Yes
4. Check the gas and air pressure → Is the gas flow symmetrical and the pressure appropriate? → No → Clean the gas path and adjust the air pressure
↓
Yes
5. Check focus and parameters → Is it optimized for the current material? → No → Re-test and optimize parameters
↓
Yes
6. Check the plate and platform → whether it is flat and clean? → No → handle the plate/platform
↓
Yes
7. Consider mechanical problems → contact professional maintenance personnel
Safety tips
- Before checking and adjusting the optical path, be sure to turn off the laser power! Avoid injuries caused by accidental laser emission.
- When cleaning optical lenses, the operation should be extremely gentle, avoid scratching the coating.
- If you are not familiar with the internal structure of the equipment, especially when adjusting the reflective lens, please be sure to contact the equipment manufacturer or professional technicians for processing.
Summary: Spark splashing to one side is usually not an independent problem, but a signal of asymmetry or imbalance in at least one of the four major elements of light, gas, material, and parameters. It is recommended to start with the simplest nozzle centering and lens cleaning. These two steps solve most of these problems. If the problem persists. Then check the parameters and hardware step by step.