Well last night I got an interesting phone call from Eve. She was cutting foam board on the laser to make Christmas ornaments. That was fine... but with foam board you need to cut it to fit inside the machine... if you don't, and it sticks out... when the parts are cut out the board in the machine now weighs less than the board sticking out of the machine. This means that unless the foam board is taped down, or propped up, it can tip up and hit the lens assembly which could cause damage.
Whenever doing a vector cut (cutting through a material) there is more power being delivered to the material than during raster marking. As a result, you want to pay particular attention to the material being cut at that time. (I had a piece of walnut catch fire and had to blow it out once.)
Eve set up a job in the machine with foam board and had the material sticking out of the machine, she started the cut, then went back to her office to finish up a drawing she was working on. The machine cut out the parts, and now that the foam board in the machine was lighter than the part sticking out, it tipped up and jammed into the optics of the machine. That wasn't very good... but because she wasn't in the room... when it caught fire, she didn't know about it until the fire alarms started going off.
By the time she got in there the main drive belt melted and burned, the top cover deformed and charred, and the entire assembly was filled with soot. I'm still in Connecticut for another week... so I don't know if the upper optical encoder is toast or if it was protected by the cover, and I don't know if the laser fused the soot to the optical glass as the beam was still at 100% power the whole time.
I'll know more when I can disassemble it and take a closer look. For now however, the laser is definitely out of service. I'm just glad the upper door didn't ignite or it could have been much worse. (Remember, there was an air compressor and a vent system pulling air through it too.)
If the optics didn't get toasted, I should have to replace the belt, replace the lid, and clean the machine, then do a calibration on it. If the optics are messed up then it gets more complicated and we will need to drive it to Colorado to be repaired. (I priced shipping the unit... $288.00 each way.) Eve is okay... that's important, and the house didn't get damaged aside from being a bit smoky so I'm thankful for that.
I'll keep you posted.