Strange problem Lead CNC 1010 Y motor reverses direction temporarily and randomly

Strange problem Lead CNC 1010 Y motor reverses direction temporarily and randomly

I will be running a job or jogging and it works perfectly fine 95% of the time, and suddenly it will reverse direction for a short period like a second or 2. Sometimes its longer and I have to stop the job It causes a very bad grinding noise naturally as the two motors are now going in opposite directions.

What can be causing this?

Also one other thing I noticed was when I try to calibrate the Y axis. The on screen controls say + 10 or -10, but the axis only travels in the negative direction to the front of the machine.

 

I went and checked the continuity of each wire and they seem okay.

Would a loose wire on one motor cause both y axis motors to only travel one way in the calibration mode specificly?

 

So if probably best to just replace the cable as a check ? Should I replace both y axis motor cables or just the one that reverses? I am assuming just the one that reverses?

 

I had found a wire I repaired before and cut the whole section out it seems to be okay now.

Although I did find a bug in the software:

When doing a Y axis calibration the buttons only go in the -10 direction. I looked in the movement log and it shows only -10 moves. Where should I report the bug that the +10 move is in the wrong direction.

 

Noted for future thanks!