I am currently using a Lulzbot Mini.
When printing, both Z-axis stepper motors erratically jerk simultaneously from time to time, resulting in printing parts that are shorter (IN HEIGHT ONLY) than designed.
What seems to be the problem?
Could be something physically binding the screws (no grease or misaligned), a loose grub screw, or failing stepper or stepper driver.
In this a Lulzbot mini 1.0
a 2.0
Or a 3.0
Even just take a picture so we know which version of the printer because each of the 3 are different
I’m no expert but in my experience it has been a loose wire to the motors either in the wiring harness or at the motherboard.
My 2 cents
Thanks for your reply!
In search of the case to the problem, I finally decided to open the box to inspect the board and electronic/electrical circuit. So with the cover o laying on the side, I turned the power switch to ON, and to my greatest surprise, “some fan” that I had never ever heard before started blowing!!! I had never heard this fan before. I then realised that electriical wires were in the way. I rearranged the wires, replaced the cover, made sure the fan worked, and the problem disappeared. It seems obvious there was a quality control issue at the time the machine was assembled.
Just to make sure my explanation is clear: the motors were jerking only after the machine had been printing for a certain time. It seems clear now that it was overheating because the fan cooling the board and circuit was not working.