Z axis not moving at setup

I assembled the machine and you can hear the z axis motor kick on but nothing is moving. Any idea on what I might have done wrong on setup?

Is the tiny set screw on the Z pulley tight ( pulley on top the Acme shaft)?

Am I reading you correctly that the motor “jolt” upon energizing the machine but no jog commands result in motor operating?

Do the X/Y axes / motors work okay?
Check that you have the Z motor wires correctly wired up / use correct wire pairs.

Or do the motor make a grinding noise when you try to jog, but no movement occur?

Was this resolved? If so what was the problem? I am having the same issue. Grinding noise but no movement - wiring is correct.

I found that the screws that go into the plastic piece that moves the z axis up and down was too tight. It had the z axis screw and plastic piece in a bind. @AlexanderKrause

Put shims under the lead screw nut. Leaving the screws loose can cause later problems in my opinion.

I loosened the screws and that solved it thank you!

Hi all please help. I have a similar issue.

My x and y axis are moving fine at setup but my z axis sort of just jerks when I try move it back and forth and the motor is getting quite hot.

Ive disconnected the actual belt leading to the lead screw to see if the motor is actually turning and still the same issue?

If stepper gets hot the current limit is set too high. This is adjusted at the stepper driver controller board.
If the rapid rate or acceleration values (GRBL value $112 and $122) are too fast the stepper will stall and make a grinding noise.

this was exactly my issue. as the material is a black delrin its prone to flexing and will cause a bind. seems maybe this should get resolved.

Thanks! Problem solved!