TAZ 4 Left Stepper moter stops stepping


our one and a half day old (and almost one and a half day long printing) new TAZ stopped working this afternoon.
It had printed about 10 layers with the left stepper not moving and the result looked ugly when we stopped it. Right now
when we try to move it in the Z-Axis, only the right stepper motor works, while the left just wiggles but doesn’t move the

Can we trouble-shoot this or do we need a new motor?


Video of the buggy z-axis with an otherwise beautiful TAZ-4 can be found here:


First thing you want to do is re-level the X axis. If you are of at an angle, you may be binding on the leadscrew and causing it to be unable to turn the motor If it is level at this point, you may have an electrical or a motor issue. Check that the motor coupler is down and tight and hasn’t partially worked loose on one of the pins. The red pin working lose for example will cause the motor to try and turn at double the expected rate, causing a bind. If you think it’s level and all the connections look right, I’d try undoing the coupler on the motor side, and see if the motor can turn freely without load. Also ensure that the leadscrew itself can still turn. It could theoretically be a bearing issue.

If none of those pan out, contact customer support. Those motors are pretty reliable though. I’ve killed exactly one of them on my older AO-100, and that was after much heavy use on the Y axis. The z axis motor barely even moves, so chances are you didn’t wear it out. I’d guess you are running into the binding issue combined with a loose fitting, but I can’t tell 100% from your video.

Thanks piercet for looking into it.

I’ve leveled the x axis a couple of times manually since then and with the motors off I can turn the two leadscrews
manually fairly easily. So they can turn and the motor is connected. Will decouple it and see if it turns under load, thanks for that suggestion.


I’ve decoupled the z-motors now from the leadscrews and while the right one still reacts perfectly to moving requests
the left one vibrates but doesn’t move. I’ll contact customer support on Monday I guess.

Thanks so much for your help!


More than likely there’s a break/loose connection somewhere along that path, on one of the four stepper motor wires. We’re responding to the ticket as well, but for everyone else’s information, you would use a multimeter to test the continuity of the two wire pairs: black and green & red and blue. If the two wire pairs are continuous, then the stepper motor is likely ok, and the problem can be found in the connector pin crimps, seating or connection, either on the harness or the board.

Thank you Orias,

that was exactly it. The connector on the motor must have been lose. It measured 47kOhms from the electronics board. Now that everything is reconnected the motor moves again nicely. Back to being a happy 3dprinter owner :wink: