Z axis not moving

[JK2000]

Hi, I just assembled my I3 pro B and clicked "auto home" to see if the motors work.
X and Y worked but one of the threaded rods is so hard to turn that the motor can't move it.
Did someone of you have this problem too and can help me to fix it?
Thanks in advance!

[William]

Hi, Are you referring to the difficulty of selecting the z-axis threaded rod itself?

You can check the following:
1. Whether the z-axis threaded rod is bent, if it is bent, it needs to be replaced in time;
2. Whether the coupling is installed correctly;
3. Whether the left and right of the z-axis are on the same horizontal line, and adjust it in time if it is tilted;
4. Check whether the brass nut installation is too tight. If it is too tight, it needs to be loosened.
For specific operations, you can refer to this: http://geeetech.com/forum/viewtopic.php?f=82&t=60931

I hope this can help you.