Cutting problems on a gerber

[martin54]

I've had the gerber doing test cuts on lots of different materials & all seemed to be progressing well until yesterday when I decided to try something a bit more complex.
Had a file for a motor mount which I was going to cut in aluminium at some stage but decided that would be a good test & rather than use ally used a bit of MDF to see how it would turn out.
Things seemed to be going well, the machine had already completed 2 full passes but on the 3rd pass it went a bit haywire & went completely off track.
After stopping the machine I sent it back to the zero co ordinates & it was miles away from where it should have been.