One of the biggest benefits of fiber over CO2 is maintenance. It is easier to perform maintenance on a fiber laser cutting machine than on a machine equipped with a CO2 laser because there is less of it required.
This means fabricators have even less of an excuse for not taking the time to perform proper maintenance on their fiber laser cutters. Unexpected downtime caused by poor maintenance is far more costly, in most cases, than taking the time to perform the proper maintenance.
A fabrication shop can significantly reduce the possibility of future problems by paying attention to common maintenance requirements. In this article, two members of Trumpf Inc.’s service team provide insight into the maintenance involved with their fiber laser machines.
Gas and lens
The first and most key variable on any fiber laser cutter is the gas quality. And it needs to be contamination free, says Roger Michaud, Trumpf’s technical support manager.
“The CO2 laser is much more forgiving than the fiber laser as far as gas purity,” says Michaud. “It is crucial that the nitrogen is contamination free. It must be clean, dry and oil free.”
The various grades of nitrogen that are available can have anywhere from 99.9 to 99.99 to 99.999 percent purity. “We call it the five/nines or the four/nines,” Michaud says. “These types of machines require medical grade gases. A purity of 5.0 has been a standard recommendation for 15 years, and we recommend this for all of our fiber laser cutters.”
The protective glass that covers the fiber lens inside the cutting unit must be cleaned weekly or daily, depending on the condition of the material being cut. The cleaning requires gloves and special fixturing and chemicals, similar to a regular lens.
The protective glass is a consumable that may last a week or a month, which also varies by material and proper care.
Just like most laser machine manufacturers, Trumpf provides a recommended preventative maintenance schedule, which every user should follow to ensure maximum performance and long machine life and eliminate unscheduled downtime.
Much of the maintenance required on a fiber laser machine is similar to that on a CO2 machine: They have the same mount and machine platform, although, often times, the fiber machine’s footprint is smaller. The big difference, therefore, is the laser medium, and fiber and CO2 require different styles of maintenance.
“We’ve eliminated the optical beam path with the fiber laser and now just have the fiber delivery system from the laser source or medium to the cutting unit,” says Jim McNamara, laser tech support supervisor at Trumpf. “All of the CO2 focusing mirrors within the processing area, as well as the laser gases, have been eliminated with the fiber delivery system. We took out several optics as far as consumables are concerned, which constitutes a huge cost savings. In eliminating the optics, we subsequently eliminated any need for their alignment.”
With solid-state lasers, the RF tubes have also been eliminated, which is another savings on consumables. Elimination of the RF cabinet means less maintenance, as well.
In addition to a reduction in consumables, overall machine cleanliness is a big part of preventative maintenance. Simple actions like wiping down the machine and controls will keep the machine operating at its best for years to come. Without proper preventative maintenance, common problems can start to occur.
“The first is contamination of the laser machine, resulting in poor cutting,” Michaud says. “Also, an unclean environment can cause premature wearing of components, such as the racks, bellows and even the laser.”
Neglecting to change the water in the cooling system can also cause blockages and overheating. Preventative maintenance includes changing the water on a yearly basis and using the proper chemicals.
Water filters should be changed on a six-month interval. And the same is true for the gas filters. Furthermore, dust collector filters need to be changed on an as-needed basis. These requirements, however, are all required with CO2 laser cutters, as well.
The beauty of many modern machine interfaces is that the operator can be alerted to suggested maintenance intervals. For example, the controls can prompt him to check the lubrication or the belt tension after so many hours. To further ease the process, the machine also provides maintenance check points.
Most laser machine manufacturers, including Trumpf, offer service contracts. And while not all take advantage, “we have about 20 percent of our active machine install base covered,” Michaud says.
If the fabricator is experiencing a problem, when it is time to call in the service tech?
“Trumpf has an 80 percent success rate of fixing all laser machines over the phone,” Michaud notes. “Many times, we can dial into that machine and walk the operator through an issue. We can see on the screen how many maintenance intervals have transpired. A lot of times, there’s an error code, and we can pull up the file to see every error on the machine.”
To prepare for a maintenance visit, the laser machine should be clean and wiped down. For a water change, the fabricator should have deionized water on site. Having all of the right chemicals in the maintenance kit is also recommended.
When Trumpf sells a machine, it provides training seats on how to run the machine, which include the proper daily maintenance. The accompanying manual provides all the maintenance check points, and the operator can always refer back to it to see what points to activate at what time.
Trumpf also provides a list of maintenance tools the operator will need. In addition to the cleaning kits and lubrications, other tools include a water conductivity meter to check the water and optical paper for spot image tests.
Each individual fabrication shop must find the best solution to properly manage maintenance on their fiber laser machine. But they will quickly learn that performing regular maintenance results in a more consistent, reliable and cost-effective operation. In the short run, proper maintenance prevents unexpected downtime and in the long run, extends the life of the laser cutting machine.