The primary maintenance differences between CO2 and fiber lasers are the optics inside the resonator and in the beam delivery system. All CO2 lasers have resonator optics that help generate and intensify the laser beam; most fiber lasers do not. All CO2 lasers have beam path optics (bend mirrors) that deliver the laser beam from the resonator to the cutting head. On the other hand, fiber lasers employ a fiber optic cable to deliver the laser beam from the resonator to the cutting head, eliminating the need for bend mirrors.
The CO2 laser’s bend mirrors are also enclosed in beam path bellows that are susceptible to holes from constant movement and back reflections and they must be replaced periodically. Beam path optics can also become misaligned from serious head crashes due to part tip-ups. All optics must be cleaned, realigned and periodically replaced to maintain optimum cutting efficiency. However, CO2 lasers are more forgiving in general and their cutting head optics are less sensitive to dusty environments than their fiber laser counterparts.
While there are far less preventive maintenance requirements with fiber lasers, cleanliness and strict adherence to factory optic cleaning and maintenance procedures and performing those tasks in a controlled, dust-free environment are critical to a fiber’s successful operation.
If you employ a fiber laser take care to pay attention to some often overlooked maintenance areas.
- Slat build-up is critical. When cut parts tip up as a result of excess slat you run the risk of the laser head crashing in to that protruding part. This can cause serious damage to the laser head resulting in thousands of dollars for replacement.
- When cleaning the lens and lens window be sure to take the time to do it thoroughly and correctly using proper cleaning supplies.
- Also, while substituting after-market lenses, lens windows, nozzles, insulators, or non-spec consumables might save you a few dollars, in the long run it’s always best to stick with high-quality OEM parts designed especially for your machine.
The same can be said for CO2 lasers. Opting for cheaper parts will usually come back to haunt you in the long run. We often see problems stemming from a failure to have the chiller serviced annually by an industrial chiller service company or failure to replace beam path bellows that may have holes or tears. Laser gas is another area that’s often over looked - Running low or out of laser gas can contaminate the resonator.
Patrick Medlin - President, Advanced Technology Sales & Service
1130 Tarrant Rd.
Greensboro, NC 27409