Milling machine stepper axis shuts down with following error

I am running steppers on a VMC with a Mesa 5i25 and a 7i76 breakout board. It does not use encoders. This machine has run just fine for several years now. I went to start it up a few days ago and the y axis moves with jog but herky jerky and sometimes keeps moving a little after I release the jog button I can move the axis a little and then linuxcnc shuts down with a error message "following error". I switched inputs on the stepper drive and the problem follows the axis so I know it is not the drive or the motor. The wiring looks okay. I re-seated the 5i25 board in the motherboard and that made no difference. Could this be a bad 5i25 or 7i76? Or could my computer work in all other ways but not send a clean signal for one axis? Has anyone had this kind of problem?

Sounds like the PID stuff in the ini file has been edited, open the ini file and compare those values to the working axis/joints.

Yes, the .ini file is rewritten every time LinuxCNC is closed. It is possible it got corrupted. Hopefully, you have a backup copy of the entire set of configs files.
If not, you should do so once you get it fixed.

Jon

I will check those files and report back on results. I do have backups. Thanks for the help.

Jack

jmelson wrote: Yes, the .ini file is rewritten every time LinuxCNC is closed.

Is it? Why would it do that?

Ummm, maybe this is old (obsolete) knowledge. Definitely the vars file is rewritten at every close, with the axis offsets, etc. At least at one time in the distant past, the .ini file was also re-written for some reason. And, occasionally, it got clobbered!

Jon