[EricH]

I was taking a shop class at a community college, and we were all tramming in mill heads. Somebody turned on the mill to move the sweep bar to the other side (you're supposed to just grab it and swing it). 18" long sweep bar... gauge on the end... spinning at whatever the mill was set to. This lasted a couple of seconds at the most before somebody got to the power switch, but the damage was done.

Nobody got hurt, but the gauge was ruined, and the student didn't come back after that, whether by his own choice or by the instructor's I don't know. I found the needle at the near end of the shop; I think the glass or part of it was near the chip bin near where I'd been a few minutes earlier.