Z is having issus

Hi all,

Im testing prints on TAZ6. It starts about fine but half way through the prints, the z-axis becomes inbalanced (usually the right side falls behind) and the print essential fail. Any suggestions?

Pull the electrical box cover off and swap the Z motor plugs around and see if the problem switches sides. The motors share a connection, so it shouldn’t make a difference, but if it does switch sides, it means the error is on the board, likely between the driver and the harnesses. If you’re lucky, just a bad solder joint on the Z harness or pins that can be checked and repaired.

If the error stays on the same side, then it could point to a motor, problem in the wires, motor, or mechanical interference (frame out of square, damaged threads on the lead screws, etc.)

After letting the machine sit, use the taz screen to manually raise the Z axis and see if it lags/binds. That should narrow it down to the wires or motor. Motor is easy to replace and fairly cheap, but diagnosing which of those wires is bad is just patience and a multimeter.

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The whole detail is very helpful I was also in search of this kind of a solution. Thank you for this sincere help!

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thanks for the info. It doesn’t seem like the motor is the problem. Everything seems to be moving as it should. Does that seem to point more to a board issue?

Could you be more specific on the results of each of the troubleshooting steps listed earlier?

Ok. I wanna make sure I cover everything. So I ran the test print. It will get to a point where the motors come out of alignment. So X and Y will work but Z on the right side lags behind. I’ve noticed while it’s running, that it (right motor) does something seems jerky or running slower. Not rotating equal with left motor. I have to abort the print and physically rotate the thread to align the axis again.

Checking wiring: side does not seem to change and everything seems to be firmly connected. I don’t notice any loose/broken wires or 5-pins

Manual movement: I have moved the Z through the LCD screen and (after aligning and checking height on both sides) the Z works fine with rising and lowering. So the real issue is during a print.

The printer still won’t read SD cards either so I’m wondering if i still installed something wrong on the motherboard maybe im missing something.

Nema 17 motors are pretty cheap ( NEMA 17 Stepper Motor, LDO - INCLUDING Adapter | https://shop.lulzbot.com), so it’s worth it to just pick up a couple and swap both Z’s out to eliminate them as a point of failure.

This can also be caused by binding in your rail system or lead screw.
During a print things are moving faster and can stall out a stepper where you loose steps. I just dealt with this. Getting 2 new steppers are cheap insurance but also I would disconnect both of your lead screws from a axis mount when the machine is at 0. Then you can use your hands to raise and lower the x axis system and see if there is binding. It should be nice and smooth through the whole motion up and down. Then you can also spin each of your lead screws by hand to be sure both of those are nice and smooth and there is not a rough spot or they are gunked up with old grease and dust somewhere. If there is enough binding the steppers will move when slow and little commands. Then when the speed is cranked up during a print it goes over the edge and starts to loose steps.