I bought a 54" Desay Master Cutter, and it had a really interesting feature...the limit switches are connected to the stepper board, but nothing tells the brain that it has hit the outer limit of it's size.
What this means is if you acidentally send a file that is too large for the plotter, the head will scream to the very outer limit of the plotter, where the eye senses the limit, shuts off the stepper motor, but the software keeps sending the commands, and then the stepper turns back on, then the eye shuts it off etc...
It would actually hit the outer wall of the plotter with a really loud clack, over and over again. It would jump the wheels off the track and not stop. It sounded like those 2 balls on a string that kids used to use called clackers. Really pounding the crap out of the head, walloping it against the side of the plotter.
But the worst thing was it just would not track. It would run 10' and then veer off to the right or left, or it would go 2' and veer off to the right...I tried everything to make it track, and I know most of the tricks-it just f**ing sucked big time!
I did not like the machine...so I finished a 30 billboard contract (with much difficulty) and returned it, minus 20%, and bought a Roland Versacam 54.
P