Stepper motor trouble shoot

[NB Forrest]

My Z axis motor just quit. When I jog down or up Mach3 shows movement but the motor is not turning. The green light on the controller is on and the wires from the controller are snug and the wires to the stepper motor are plugged in firmly. What is the first thing I need to measure? Obviously either the motor has gone bad or it is not getting pulses from the controller but I don't know how or what to meter.

[plasmanewbie]

I would plug the z axis motor into the x axis driver and then jog the x axis. Be sure to unlpug power to the controller before unplugging motors from drives. If the z motor moves the motor is good and the driver is bad.

[tcaudle]

Stepper motors are REALLY simply devices. Two coils of wire a big magnet and a couple of bearings. Twin failure of BOTH coils at the same time is incredibly rare and a single failer of one coil still get motor noise and vibration.
Musch more common is a cable or connection issue OR a defective Driver. Each driver has a power LED that should be on.
As stated a quick swap of the Z into the X or Y will show you if its the moor/cable .
If it runs in X then its BEFORE the motor. Driver or the signals
If the motor :locks when you power up it PROBABLY not the driver . If its not the driver it the signals. With no other inforamtion that is aas much help as we can offer/ . If its a CandCNC controller less than 10 years old than Z is typpically controlled though the DTHC even for jogging. There are ways to test that but ti depends on the model of controller

[adbuch]

My Z axis motor just quit. When I jog down or up Mach3 shows movement but the motor is not turning. The green light on the controller is on and the wires from the controller are snug and the wires to the stepper motor are plugged in firmly. What is the first thing I need to measure? Obviously either the motor has gone bad or it is not getting pulses from the controller but I don't know how or what to meter.

You could use a multimeter to check the motor windings for open circuit, short circuit, or higher than normal resistance.
David

[plasmanewbie]

Just curious if you were able to find out the issue with your Z axis?

[NB Forrest]

I couldn't find any lose connections. When I changed the y axis motor controller with the z axis I could move the z axis but not the y axis. That points me to either a bad connection or the BOB or a bad motor controller. I'm going to install a new BOB. If that doesn't fix it I will change the motor controller.

[tcaudle]

So Y axis driver runs Z. Z axis driver does NOT run Y.
Open the Hub Utility and make sure you have comms to the DTHC (Device) and open the Device Testing and settings and JOG the Z using that instead of from CommandCNC....if it moves than its missing the signal from the BoB to the DTHC. If it fails to jog from Hub Utility or you cant see the DTHC in Hub Utility you may have a bad DTHC

With out more information about the hardware you will have to physically swap the drivers to narrow it down or scatter shoot and replace the driver and hope.....

Troubleshooting older MACH3 based controllers and hardware is different than our newer more current models that use LINUX and CommandCNC

[NB Forrest]

Turns out it was a lose P+ wire. When I initially tugged on it I thought I felt resistance but I believe it was the other wires feeling snug. I didn't want to pull too hard on it but when I started to remove the wires to install another BOB I started with the z axis wires first and sure enough, the wire was lose. I put another connector on the wire and reinstalled into the BOB lug and there you go, movement on the z again. Thank you for your help. I am completely new to all of this and I'm learning. I am so appreciative of this forum.

[tcaudle]

I will note this on your duplicate posts on our Support Forum