OK, interesting day had my first real fire in the cabinet today. I was rastering a large acrylic panel today 22" X 30" (2 hours +) and when it was time to vector cut the finished piece, the panel flamed out rather badly. Ruined the panel but I was standing within 5 feet of the machine and was able to hit it with the CO2 extinguisher right away. I've vector cut peices this large many times before but I'm thinking that the amount of dust from the rastering was the main culprit. Used the same setting as many times in the past.
Three items I believe contributed to this. (1) This was a paper backed 1/4" acrylic versus the less expensive plastic covered. (2) LOTS of raster debris even with the air assist pumping pretty well clearing it away from the beam as it went. (3) I removed a front panel to allow a larger piece of acrylic to sit on the table. There was a lot more air pulling through the cabinet because of this and what may have saved the machine.
So if you think it can't happen to you...well I'm living proof.
Happy New Year and stay safe tomorrow night!