Cutter head belt

[billkluger]

While half way done with a project, the cutter head belt on my CW popped off. I was able to put it back in place, however when I restarted the project, the CW didn't know where it was at and was carving the bottom of the piece in the middle. As soon as I realized this I stopped the project and the CW read Y-Axis Install or Y-Axis Stall, I'm not sure, it only flashed for a second before going to the main menu.
Is there any specific reason for the belt popping off? What does the Y-axis stuff mean? Will it correct itself or is it something that needs to be corrected manually?
This is the first time anything like this has happened. I just figured out how to make everything work out the way I wanted it to and now this happens! Very frustrating!

[Jeff_Birt]

Your Z-truck might be a bit loose. This would lower the tension on the belt and allow it to jump off. You'll need to pull the top of the machine off (see the very first thread in the troubleshooting section for a PDF on how to remove the top.) There are two screws that secure the motor/gearbox that are installed from the left (left, if you are facing keypad) side, and a screw through a spring on the top. You need to snug up (not tighten) the screws holding the motor on and then adjust the tension screw so that there is about 1/16" flex at the center of the Z-belt. Then tighten the motor screws.