[InsaneEPP]

If anyone can help me find out what is causing this I would be extremely grateful. I added a differential driver to my open ended encoders to reduce noise, etc. That worked well. While I was rewiring the encoders I rerouted everything so the power and signal lines were in separate energy chains. There are a couple of spots where they get within 6" or so, but are usually at least a foot apart.

The servos are rock solid when not commanded to move. If I run a part program, they do fine for a minute or so, but then the Y and X axes will pause and start/accellerate violently. The machine start rocking all over the place. I don't think it is noise because I wouldn't think the servos would just sit still for .25-.5 seconds. It also looks like they go back to the correct position. I read that if the drives are not cooled well this could happen. I felt the drives (as best as I could) while mounted and they did not feel hot. I added several heat sinks and a large fan to the drives, but that has not corrected the problem.

Possible issues:

I do not have shielded cable running to the servos. I called around last week and no one carries 10 AWG 2 conductor shielded cable. Anyone have a source? Not sure if this is the reason for my problem.

Loose power connection to the servo/drive? I wouldn't think this is a problem since it seems to be fine initially.

Driver issue? I have 990Hs. My servos are 10A continuous and I am running them at 67V. I also read in the driver docs to "Make sure that no motor wires are routed above or close to the servo drive." I don't have power to the servos routed near the drivers, but like I said before, it is unshielded so perhaps this is limiting the current to the servos?

Am I missing something? Is this really noise or what?