There is a plate under the top cover, which breaks a sensor beam on the cutter as it moves to the zero zero point. When I took the top off, I could bend the plate back into place so as the cutter head moved, the sensor beam was broken, rather than the whole head running into the plate.
The problem was "probably" caused by a student leaning on the top of the machine.
The problem was "probably" caused by a student leaning on the top of the machine.
SJC