Milling machine stepper axis shuts down due to following error

[max225]

I'm running a stepper on a VMC with a Mesa 5i25 and 7i76 breakout board. It does not use encoders. I've had this machine running for several years now. A few days ago I went to start it up and the y axis moves with the slow speed but is very jerky and sometimes continues to move after I release the slow speed button and I can move the axis a bit and then linuxcnc shuts down with the error message "following error".
I switched the inputs on the stepper motor driver and the problem follows the axis so I know it's not a problem with the driver or the motor. The wiring looks ok. I re-installed the 5i25 board on the motherboard but nothing changes. Could this be a bad 5i25 or 7i76? Or could my computer be working in some other way but not sending a clean signal for one axis? Has anyone experienced this kind of problem?

[Clive S]

I'm running a stepper on a VMC with a Mesa 5i25 and 7i76 breakout board. It does not use encoders. I've had this machine running for several years now. A few days ago I went to start it up and the y axis moves with the slow speed but is very jerky and sometimes continues to move after I release the slow speed button and I can move the axis a bit and then linuxcnc shuts down with the error message "following error".
I switched the inputs on the stepper motor driver and the problem follows the axis so I know it's not a problem with the driver or the motor. The wiring looks ok. I re-installed the 5i25 board on the motherboard but nothing changes. Could this be a bad 5i25 or 7i76? Or could my computer be working in some other way but not sending a clean signal for one axis? Has anyone experienced this kind of problem?

Welcome to the forum. This might get you more answers on the linuxcnc forum https://forum.linuxcnc.org/forum