Y Axis changes mid cut +/-1" with crunchy sound

[42SqFtWoodworks (Nate)]

So I was working on a test piece to do a production run of Bear shape designs. During the clearing pass, on the 4 bear (Top Left), an hour thirty plus into the job the Y jumped +1" from home. I stop, reseated the cables and decided to vcarve the first bear (Bottom Left), 5 minutes in it jumped -1" from home. Arg…

I cleaned the rails, reseated all the cable on both sides, and power cycled the controller. Third time was not the charm. 3 minute in to bear 2(Bottom Right) it jumped +1" from home.

I can hear when it happens, there is a crunchy sound in a Y move. Everything was cleaned and oiled a few weeks ago and I’m not a heavy user, maybe 5-10 hours a week. I’m on V1.0.9

Any thoughts or prior experience would be helpful.

[pwpacp (Phil)]

Just a couple of thoughts.

To me it starts from the point of determining if it is a mechanical vs electrical issue.

Maybe try letting the file run with no bit then gently wiggling the cable ends to see if the connection gets wonky from vibration.

Mechanically, you could try to move the axis while the power is off to see if there is unusual resistance. When I move mine like that the action is quite smooth and consistent.