If you wear safety glasses regularly, as we all do here, you’ll know they quickly get dirty. While a few guys seem happy to walk around in a fog, most of us prefer to keep our glasses clean. When we can see better we work better, or at least that’s the idea.
It’s the same for a laser cutting machine. The laser light passes through an optical window on its way to the workpiece. If that window isn’t clean not all the light gets through and beam quality suffers. To prevent that we do laser machine maintenance. The optics are the most critical part of the machine, but good maintenance involves more than just window cleaning. Here’s how we look after our laser cutters.
Understanding the Laser Cutting Machines
“Laser” is short for “Light Amplification by Stimulated Emission of Radiation.” Light is created in a unit called the “resonator.” That needs cooling to ensure reliable, consistent operation, so the machines have a chiller system.
The light is directed out to the cutting point by special mirrors and optics. These focus it down to to a very small spot, dramatically increasing the energy per unit area. To improve performance we surround the beam with an assist gas. This raises the cutting temperature, blows away molten material and improves edge quality.
There’s also a motion control system for moving the sheet under the laser head. This has ballscrews and drives, just like any other machine tool.
The Importance of Laser Machine Maintenance
As most of us learned long ago, if you skip regular maintenance you’ll get a breakdown. If that happens deliveries are delayed and tempers fray. We avoid those problems by ensuring every piece of equipment – laser cutting machines included – gets regular attention.
Another benefit of looking after machinery is that it lasts longer. New laser cutting machines are very expensive, so we’re determined to maximize the life we get out of ours.
Lack of maintenance also hits productivity and quality. Remember the “Sharpening the axe” story? (Read “5 Maintenance Tips You Can Do Today to Extend the Life of your Machining Tools” if you don’t.) Well a laser machine in good condition cuts faster, cleaner and more precisely. That means we get more work through each machine with less clean-up and weld prep.
Maintaining our Laser Cutting Machines
There are some basics that apply to every machine, not just the laser cutters. These include:
- Visual inspections. Look for wear, leaks or signs of deterioration. Bellows and wipers on slideways and over ballscrews are a good example.
- Lubrication. Top up and replace fluids as the manufacturers recommend.
- Filter replacement. Both air and oil filters.
- Cleanliness. This helps keep machines in good condition.
Then there are things specific to laser cutters. These are:
- Cleaning optics. Laser cutting generates smoke which clouds the window and reduces beam quality. The optics need cleaning carefully as it’s essential to avoid creating scratches.
- Beam quality testing. Laser manufacturers do this with a beam analyzer. An easier approach for a shop like ours is to do regular test cuts – some call them burn profiles – and compare how the beam cuts today with pieces cut when the machine was new. It’s a simple, visual way of seeing if the beam has changed.
- Chiller maintenance. The water needs changing periodically and must have microbiobial chemicals added. Plus, the cooling coils need cleaning to keep it working efficiently.
- Assist gas checks. The gas must be clean and dry. Shop air is popular as an assist gas, so it’s important to check filters and moisture traps are all working as they should.
Doing a Better Job
Good maintenance disciplines are an important part of running any fabrication shop, and laser cutting machines demand special consideration. In addition to the checks every machine tool needs, the beam generation and delivery systems need regular attention. We stay on top of these jobs because it helps us work better. Well maintained equipment breaks down less often and produces higher quality results, which is what we all want.