Laser cutting wood, what if it's not cut through?

When using the CO₂ laser cutting series control system, if you encounter a situation where the material cannot be cut through, you can follow the steps below to troubleshoot and make improvements:

1. Is the Laser Tube Aged: CO₂ laser tubes have a defined lifespan. Their output power gradually degrades with use. If the laser tube is aged, the actual energy reaching the material surface will be insufficient even with the same parameter settings as before. This can be judged by measuring the actual output power with a power meter or comparing the cutting results with those from a new tube. If aging is confirmed, replace it with a new laser tube.

2. Is the Focusing Lens Contaminated: The focusing lens is located at the end of the laser path and is directly responsible for converging the laser beam to a point. If the lens is contaminated by smoke, tar, or moisture generated during wood cutting, it will severely reduce light transmittance and may cause diffuse reflection, leading to a significant decrease in energy density at the focal point. It should be cleaned regularly (recommended every 8-12 hours of operation) carefully using specialized lens cleaner and lens wipes to maintain high cleanliness.

3. Are the Reflective Mirrors Contaminated: After the laser beam is emitted from the tube, it typically passes through several reflective mirrors to change direction. Contamination on the surface of any mirror will cause energy loss during laser transmission. All reflective mirrors should be inspected to ensure their surfaces are clean and dust-free. The cleaning method is similar to that for the focusing lens, but the operation must be gentler to prevent damaging the mirror coating.

4. Is the Optical Path Misaligned: The laser beam must travel precisely through the center of all reflective mirrors and hit the center of the focusing lens vertically after leaving the laser tube. If the optical path is misaligned (e.g., due to equipment vibration or impact causing mirror mount displacement), the beam cannot be perfectly focused, resulting in dispersed energy, a larger spot size, and a rough, weak cut. It is necessary to recalibrate the entire optical path system according to the equipment manual's guidance using calibration tools (such as a red dot pointer or the tape burn method). This is the foundation for ensuring cutting efficiency.

5. Is the Power Output Appropriate: The power percentage set in the software must match the material. For thicker or harder woods (like oak, beech), higher power settings are required. Parameter testing is recommended: perform cutting tests at different power levels (e.g., 60%, 80%, 100%) at a fixed speed to find the minimum effective power that can cleanly cut through, balancing efficiency and quality. Also, check if the laser power supply is working stably.

6. Is the Speed Too Fast: Feed speed and laser power must match. If the speed is too fast, the laser's dwell time on a unit area of the material is too short, and the accumulated energy is insufficient to ablate and penetrate the entire thickness. When encountering incomplete cuts, the first step should be to significantly reduce the cutting speed at the existing power level. Typically, it's necessary to refer to a "Power/Speed/Material Thickness Reference Chart" or create your own test grid to optimize and find the best combination.

7. Is the Material Too Thick or of Uneven Density: Each laser machine has its maximum effective cutting thickness, determined by its rated power. Attempting to cut wood exceeding this limit will inevitably fail to penetrate. Furthermore, uneven wood density (e.g., knots, dense grain areas) also increases cutting difficulty. The solutions are: First, confirm whether the material thickness is within the machine's capability. Second, for thicker workpieces, try using multiple passes (reducing the stress per pass) or adjusting the focus appropriately (performing a "sacrificial cut" to optimize the focal position). For high-density areas, it may be necessary to locally reduce speed or increase power.