I read another post where someone had a flareup/fire that caused damage. We all want to maximize our time and multitask to the best of our abilities, but that just isn’t a good idea when you are running a laser. I ALWAYS stand and watch my GF when it is running. If I get bored, I get a barstool, set it in front of my machine and lay my favorite electronic device on the lid and read/whatever while having full access to the view of my worktop. Even if I am working on something inflammable I watch (keep in mind masking and the adhesives they contain can be very flammable). Below is a video I shot while doing a test on old barn wood. As you can see, most of the masking was blown off the workpiece and the piece that remained was flapping in the breeze. Within seconds of the end of the video, the tape stuck to the printhead and got pulled under the laser. Had I not been there watching I could have damaged/destroyed my machine or worse, started a fire that could have destroyed my home. The few moments away that you steal are just not worth the possible costs.
I had the same problem with some loose masking tape that got blown up into the path of the beam. Caught fire and got sucked into the exhaust fan, where it made a huge honking mess.
I love the comments from people about how “ridiculous” it is to have to watch the machine. There have been plenty of examples shared here and elsewhere of what can happen in just minutes. We haven’t lost a home or a life yet, thankfully.
Back in the early days of Lithium batteries for radio control models, fires while charging were not uncommon, so you never left them unattended while charging unless you had some kind of containment. For example, if i had a large batch to charge before an event, I would move my equipment into the drum smoker I had in the car port! One of my good friends almost lost his home as he left his stuff on charge in the garage and went inside for dinner. Fortunately, they were able to contain the damage to just that part of their home, and rebuild. Another friend of ours then invented and successfully marketed a fire-proof kevlar bag system for containing the batteries while charging.
I’m in the middle and honestly, I don’t watch my machine every second because I just can’t do it physically. If I’m doing material I’m not familiar with or running a file I consider higher risk, I’ll watch closely. But if for example I’m engraving acrylic, I just keep a more casual camera eye on it. So I’m not a hypocrite and criticize people if they don’t sit and stare at the machine for hours on end, but I will criticize them for complaining and blaming GF or someone else if things go sideways.