Z-axis lead screw issue


Hi, I am M300 user which used almost a year +.
Currently I have a problem that the Z-axis jam somewhere (NOT smooth) while manual platform UP & DOWN.
Auto-Calibration failed!
I check the lead screw, it seem to be T8 with 2mm feed pitch & length seem to be 450mmL. Correct?
It seem to be the lead screw nut worn off, OR stepper motor spoilt?
Can provide soluation?



Can you provide a video showing how the Z-axis behaves when you move the platform up and down manually (please start with the bottom position and move it up until it reaches the top). Also, can you record how it fails during autocalibration? It will be easier to provide a solution then. You can also lubricate the Z-axis screw.

Best regards


Attached herewith the video. Platform seem jam.
During auto-calibration, the difference between point can be more than few mm. strokes seem jam.
I have lubricated the screw all the time.
This unit was used almost more that a year.
Video file can’t attached. Can I send to you by e-mail?



Please send the video here:


Kind regards,