[EmergentDesigns]

I've recently bought an avid-cnc 4896,and am a little out of my comfort zone. The machine is set up and running, however the two y axis motors are not moving in sync. When I jog the machine in either y direction, one motor moves first, racking the gantry before the second motor starts moving and follows along. If I only jog a tiny bit, back and forth in both directions, the one motor will move upwards of a half inch, with the other motor not moving at all.

When cutting, straight cuts along either x or y axis are nice and straight, but arcs which engage both axes result in a very scalloped edge, as the gantry movement sorry of "bounces" along each step in the arc.

I've checked that the motors are well-engaged in the rack and pinion, and are set to similar tension (about 3 turns past finger tight on the spring-screw).

The gantry movement has been like this since I got the machine up and running, though it was still managing to cut pretty straight and accurate lines, however the last few cuts, the scalloped edges have gotten worse and worse
, leading me to believe something may be loosening. I've checked all connections that I can get to, but haven't found any obvious culprits.

Hopefully the behaviour is obvious in the following video: https://drive.google.com/file/d/1E89HE4hTJEbuXeDT7-R47t-g-vOUaeoN/view?usp=drivesdk

[EmergentDesigns]

Ok, so it occurred to me, since it's lagging in both directions, that is probably just being driven/dragged along by the one motor. I disengaged the good one, and sure enough, the other isn't turning when the machine moves.

I swapped the connections, to see if the problem was in the control box/circuitry somewhere, and no change, so the issue must be either the motor itself, or the cable, which sadly is hard wired to the motor, and runs through the gantry, so not an easy swap to test. It seems more likely to be an issue with the motor though. Any thoughts on troubleshooting the motor itself?

I should mention, the machine has nema 34 motors

[machinehop5]

...is this the machine you have?....
https://www.avidcnc.com/support/inst...r=20.2&ms=4848

[EmergentDesigns]

Yes, though it's a 4896. Same setup though...

[EmergentDesigns]

The issue seems to have resolved itself after a few rounds of unplugging and plugging, for troubleshooting, so must have been a connection issue