Hello CNC'ers!

I am running Mach4 and Pokeys57CNC.

I am at my wits end and can't track down a problem with my Xaxis stepper motor.

The problem is it just vibrates loudly and doesn't move.  (Short video attached if it let's me upload.  Yup!  That noise is the stepper motor!)

This machine had been running with no issue.  My issue started when I disassembled the machine to install new Y axis plates.  The machine was running fine (cutting then new plates I installed) before I disassembled it.  Literally all I did was re-assemble the machine and now the Xaxis won't run.  (All other axes are fine)

I won't bore everyone with all the details (of course unless you ask) however through series of elimination I thought I had it narrowed down to an aviator connector for power (A+/-, B+/-) at the stepper motor.  (Swapping stepper drivers, cables, checking stepper motor winding pairing, checked voltage, connections at stepper driver, tested motor on another axis, etc...)

Well that's not it!  I don't know what else to try.

Any hints, advice, past problems that would help would be greatly appreciated.

Thanks!

Hi,
sounds to me like you have the Step and Dir signals swapped over.

At your stepper driver temporarily disconnect the Dir signal. If the stepper/driver are good and you HAVE NOT accidentally swapped
the Step/Dir signals the stepper should move but only in one direction. Be prepared top Estop it.

If however the stepper/driver are good but you Have accidentally swapped the Step/Dir signals then I would expect the stepper to
do nothing...not even a sound.

Craig

Hi Craig,

Thank you for the feeback.  Appreciate it!

I confirmed that my DIR and Step connections were NOT swapped.  I went ahead anyway as a test and disconnected the DIR signal.  Same problem still exists.

Hmmmmm.

I am truly at a loss now.

I've attached what I have done so far to try to narrow down the problem. 

I am going to swap out the XAxis for a open loop driver and stepper that I have on the shelf.  Based on my troubleshooting it seems unlikely that it will work but I want to eliminate the board as an issue. 

Any other ideas?  It seems I am missing something very fundamental.

Thanks a bunch.

Hi,
I think the buzzing is the stepper trying to reverse direction very rapidly, as if the Dir signal is changing state very rapidly.

Does your BoB have LEDs on the outputs? If so the Step output LED should assume a slightly dim condition when a rapidly changing signal
is applied, ie  a Step signal. The Dir oupt LED should change only if you jog in the reverse direction.

Craig

Hi Craig,

No LEDs.  But I can connect to the stepper driver with setup / config software.  I had checked before with the software any there were no errors.  But I didn't monitor while I was trying to run the motor.  I'll crack it open now and check again.

Checked with software and couldn't find anything out of the ordinary

So it looks like the stepper driver is actually bad.  I connected the closed loop motor (still on my machine) with an open loop stepper driver.  The motor turns with no issues.  I then reconnected the closed loop stepper driver and back to the same problem of buzzing and no movement.

I've got a work around at least until I receive a new stepper driver.

Thanks for your time and suggestions.

All the best.  Hope you and your family are safe and healthy.