Random Joint Following Errors?

Getting seemingly random "Joint Following Errors" on my Y axis. Can't isolate with G-Code so far, routine will run fine then fail in another location.

I built a stepper system using Pico USC controller and Gecko 203v drivers, which simulates a servo system. Went through some initial headache tuning the PID values to get running smoothly without errors. X and Y axis utilize the same chain/sprocket drive setup, and identical PID values. Which is baffling to me because I am not getting errors on my X axis, which is carrying the entire gantry loads, while the Y axis is driving smaller loads. If there was a problem with acceleration values I would think the X would fail first trying to keep up.

Any ideas why one axis would fail and not the other one?

Jeff

Yes, I purchased an Intel D525M motherboard and installed a 60gb SSD based on recommendations from this forum. Latency max figure is 16000. I also purchased Pico Systems USC to help with demands of software step generation.

Jeff

Update -
This is an open-loop system without encoders, so obviously there is no way for the software to actually know what the axes are doing, so my comment on the X axis failing first was unrelated to what is actually causing the error. (I hope) I am using CAMBAM, and just getting comfortable with its interface and methodology so I think I may have come up with part of the problem. I thought I was running in constant velocity mode (G64), but noticed I was getting very inconsistent feed rates. I used the feed override to push things up since the cutter was doing quite well at this DOC. I think this was causing the machine to choke periodically, pushing beyond what the machine was capable of acceleration wise from a software point of view.

I went back to CAMBAM and ensured the constant velocity mode was set, and also increased the desired feed rate. Still not sure if CAMBAM actually does anything with that value or not, since it knows nothing about my machines acceleration and velocity capabilites. Anyway, when I did a dry run with the new code, so far, I think the results are favorable, (no errors). Just in case, I am going to dive into HALSCOPE and re-run some PID tests to see what tweaks I can make to tighten up the control loop.

Still baffled why I did not get errors in the X axis.....

Jeff

John, the Pico board does not use software step generation so that is completely NA. Did you read the Pico FAQ under the driver board section of this forum? It explains how this system works.

Yes, I was referring to G64 P, sorry just dropped the "P" when I was typing. I think this may be the main issue, so I am hopeful I have it under control now

You mentioned the latency numbers, I was getting numbers well below 8000 at all times until I ran gixgears, then it spiked to 16000. Are you running onboard video? If so then it looks like I do need to update my BIOS just to make sure I have the latest and greatest. Thanks for that tip.

Jeff