Never leave a laser cutter unattended!
In this article, I am going to cover why you should never leave a laser cutter running unattended.
Laser cutters work by burning (vaporising) material away from the workpiece in a controlled manner. Usually, this will work without a problem, but what happens if something goes wrong?
This is an experience I had recently while I was using my K40 laser cutter. Luckily I was still in my workshop working on another project, however significant my K40 sustained significant damage in less than a couple of minutes:
“I’ve cut this project lots of times without issue. Can’t I just leave it running on its own?”
At the time of this incident, I was using my K40 to cut through a piece of 3mm thick coloured acrylic. I was using a speed of 10mm/second and two passes. I was making one of my most popular products, which I have cut hundreds of times without issue. I’m not sure what changed but something did!
I’d set my K40 running and was working on another project in my workshop. I was using a sander so couldn’t hear any change in noise etc but I was glancing over at the K40 every minute or so. Imagine my shock when I saw flames coming through the viewing window!
When I bought my K40 I also made sure I bought a CO2 fire extinguisher. I’d never had to use it before but thankfully it was close by a ready to go! A couple of short blasts of the extinguisher put the fire out. I was conscious not to overuse the CO2 extinguisher as I didn’t want to cause any more damage to the machine.
Damage Report
Thankfully my K40 didn’t sustain any serious damage, however it did need some new parts:
Air assist nozzle
As you can see, the air assist nozzle was completely destroyed. I had to purchase a new one; luckily they are very cheap. The main downside of this was having to pause production for a couple of days while I waited for the new one to be delivered. It is probably worth keeping a spare one in stock in future.
Air assist tubing
The air assist tubing had burnt back into a melted mess. I had quite a lot of extra length on my air assist tubing so I simply made a straight cut after the damaged part of the tubing and reattached it.
Viewing window
The viewing window was ruined with a large hole melted out of it.
I removed the ruined piece by undoing the bolts on the inside of the cover that hold the viewing window brackets in place:
Here is the K40 with the new, clear viewing window:
Laser head/focus lens/mirror
The mirror and focus lens within the laser head were sooted up with smoke however after a quick clean they were perfectly usable again.
Conclusion
Hopefully, the images in this article make it clear how quickly a laser cutter can transform from a happily working machine into a blazing inferno. If I hadn’t been at hand to put the fire out things would have escalated very quickly.
Here are some lessons to take away:
- Never leave a laser cutter running unattended. It won’t take long for a small fire to develop into a huge blaze.
- Keep a fire extinguisher nearby to use in case of any fires occurring. I use a CO2 fire extinguisher like this. Just be aware that heavy use of a CO2 extinguisher could damage your laser cutter even more.
- Consider keeping spare parts for your laser cutter, that way if anything breaks down you can be up and running again with minimal downtime.
For more on K40 / laser cutter safety, check out this article.