Took the class on the new machine last night (the machine is awesome, btw). It might not be a bad idea to post a sign (or just vinyl?) on the wall by the exhaust fan switch to remind users that (a) this is the exhaust fan switch and (b) turn it on before operating the Dynatorch. While the training last night was otherwise excellent, that got omitted. Thankfully, I was the only one in metal shop during the time I was operating the Dynatorch without turning on the fan, then I realized “hey, we used to turn on the exhaust on the old plasma cutter, I’d bet this is the same deal.” So the air quality got crappy for me for a few minutes, and then it was all better. Cheers.