Here I am minding my own business, making cool stuff for cool people as I do. I am quite happy you see, I have recently refurbished a MultiCam Mg103 to working order and it is a lovely machine. My previous machine I am still refurbishing 1 and 1/2 years later. Axyz custom 4008 circa 199x, but that is a nightmare all in its own.

I have the mg103 and for about 2 weeks it was great! I setup a DNC and feeding jobs directly from my pc is a breeze and makes my life easier. The thing is halfway through a job it tripped it's y-limit and reset in the middle of a fast-move. Moved the home for my job and cut up my already finished pieces into a little mess. Now there are some mister nozzles (metal) that were positioned near where the limit switch activates so initially I thought it was that. I moved them and the machine continued as normal. Now about a week later the issue has resurfaced with a vengeance. In the course of testing I found that when I home the machine to the limit sensors and manually jog it, it will travel all the way down the y axis to its soft limit. When I fast travel to max y it will travel 65% of the way and abruptly stall as if it hit a hard limit. I have literally just started examining the issue, and have the ball screw cover off. I have three working theories

a. There is a piece of material causing resistance on the track. The resistance is only high enough to stop the machine when fast travel is used
b. The stepper motor driving the ballscrew is missing steps when instructions are fed at the rate of the fast travel. Or is internally damaged and fast travel in some way causes it to work beyond whatever the limiting factor is.
c. The carriage that rides along the ball screw or one of the threaded apertures is damaged in some way.

Does anybody have experience with this type of issue? Also is it possible that the machine acceleration rate may be the culprit. I won't count that as a theory bc I don't know enough about it yet.

Any help will be greatly appreciated. Brainstorming is key.