What Can Cause the Ender 3 (Pro/V2) Z-Axis Not to Move?

Even though we can all agree that 3D printing is a magical process that creates exciting possibilities in the comfort of our own homes, it’s also undeniable that it comes with its fair share of problems, and most likely a higher amount than you would face in any other hobby.

Due to the complex nature of a 3D printer, the problems can show up in many shapes or forms, such as a straightforward software issue where the culprit is apparent or a complex electrical problem that requires a decent amount of technical knowledge in electronics.

In today’s article, we will analyze one of the most dreaded problems you can face while 3D printing with your Ender 3, in particular, where the Z-axis entirely locks up and refuses to move either up or down, causing the printing process to fail and rendering your 3D printer inoperational.

So, what can cause your Ender 3’s Z-axis to not move during the printing process?

Below, we have listed the most common culprits behind the issue of the Ender 3 Z-axis not moving:

  • Overly tightened Z-axis eccentric nuts
  • Stuck Z-axis lead screw (Z-rod)
  • Wiring issues between the Z-axis stepper driver and the Z-axis motor
  • Z endstop stuck in closed position
  • Firmware-related problems
  • Malfunctioning Z-axis stepper driver or motor

In the upcoming sections, we will take a deeper look at the reasons behind your Ender 3’s Z-axis not moving, go through the potential solutions, and find out the most optimal lubricant choice for the Z-rod that is responsible for the Z-axis movement.

What Can Cause the Ender 3 (Pro/V2) Z-Axis Not to Move?

As with any other problem involving many distinct culprits, finding the root cause behind the issue is the first step to applying the correct solution, which will require knowledge about each culprit individually.

Below, you can find the common factors that can prevent the Z-axis of your Ender 3 from moving, alongside detailed descriptions that explain the reasoning:

  • The Z-axis eccentric nuts are overly tightened. Overly tightened eccentric nuts will cause the rollers to become too firmly attached to the rail they are supposed to slide freely on, which constricts their movement. In severe cases, this can completely prevent the Z-axis of your Ender 3 from moving, as the motion that the stepper motor supplies may not be enough to move the rollers in such a state. In this case, you may hear clicking sounds from the stepper motor and grinding sounds from the rollers.
  • The Z-axis lead screw (Z-rod) is stuck. The Z-axis lead screw is directly responsible for transferring the movements of the Z-stepper motor to the Z-axis, and in the case where it’s stuck due to reasons such as being over-tightened or crooked, the Z-axis won’t be able to move. In this case, you may hear clicking sounds from the stepper motor as it struggles to turn the lead screw.
  • There are wiring problems between the Z-axis stepper driver and the Z-axis stepper motor. The wires between the Z-axis stepper driver and the Z-axis stepper motor being damaged or loose will prevent the appropriate signals from reaching the stepper motor, stopping the Z-axis from making any movements. In this case, the Z-axis stepper most likely wouldn’t be operating at all and not even make the humming sounds it usually makes.
  • The Z-axis endstop is stuck in a closed position. The Z-axis endstop being stuck in a closed position will cause your Ender 3 to stop any Z-axis movement before it can even start, as it will make your 3D printer think that the Z-axis is already at the lowest possible position. In this case, only downward movement should be limited (and homing), but you should be able to move the Z-axis up.
  • Firmware-related issues are preventing the Z-axis from moving. As the firmware is essentially the component that gives the necessary instructions for the Z-axis to move, a firmware bug can prevent the Z-axis from moving. In this case, the most likely scenario is nothing to happen when you issue the movement command.
  • The Z-axis stepper driver or the Z-axis stepper motor is malfunctioning. Finally, it goes without saying that an issue with either the Z-axis stepper driver or the Z-axis stepper motor itself can prevent the Z-axis from moving, as it’s essential for both of these components to be functional for any movement to occur.

How to Fix the Issue of Ender 3 (Pro/V2) Z-Axis Not Moving?

Getting the Z-axis of your Ender 3 to move again can be a challenging process due to the many potential culprits involved, especially considering that the problem can reside in both the electrical and mechanical parts.

Here are the potential solutions we recommend applying to fix the issue of the Z-axis of your Ender 3 not moving:

  1. Loosen the Z-axis eccentric nuts. You can find the Z-axis eccentric nuts behind the Z-axis rollers, which you can turn with the wrench that was included with your Ender 3. One thing to keep in mind is that eccentric nuts are different than standard nuts, and turning them 360 degrees in either direction will bring them to the same exact position that you started at instead of loosening or tightening them. As a result, we recommend making slight turns in either direction and checking its effects on the tightness of the rollers.
  2. Loosen the grub screws on the coupler that connects the Z-axis lead screw to the Z-axis stepper motor. You can find the grub screws in the holes located on the coupler and quickly loosen them with a hex key to give the Z-axis lead screw more room for movement. As the screws being too loose is also an issue, it’s vital to loosen them to a balanced level.
  3. Loosen the screws on the extruder motor bracket. You will find these two screws on the left and the right side of the extruder motor bracket (the piece that the extruder is attached to and that the Z-rod goes through), and loosening them can free an otherwise stuck Z-rod.
  4. Clean and lubricate the Z-axis lead screw. For this process, we recommend completely separating the Z-axis lead screw from your Ender 3, thoroughly cleaning it with some isopropyl alcohol until there is more grime left, and evenly lubricating it before putting it back on. After putting the Z-rod back on, move the Z-axis up and down a few times to distribute the lubricant further.
  5. Redo the wiring between the Z-axis stepper driver and the Z-axis motor and inspect the wires for damage. It’s vital to ensure that the wires are not damaged and that the wiring is not loose on either end. For good measure, we recommend replacing the wires for testing purposes even if you don’t see any issues.
  6. Unstuck the Z endstop. To unstuck the Z endstop, ensure that the metallic piece rests in the open position (not in contact with the mechanical button) and that the mechanical button is not stuck inside. If the button is stuck, you can most likely bring it out by pushing it further or using a pin to release it from its stuck state.
  7. Update the firmware. We highly recommend downloading an up-to-date version of Marlin from the official source, building it yourself, and flashing it to your Ender 3 to eliminate the possibility of any firmware-related issues.
  8. Test the Z-axis motor and replace it if needed. To test the Z-axis stepper motor, you can remove the wire that goes into it from the Z-axis stepper driver and then connect the stepper driver that belongs to another axis. If the motor still doesn’t work, it’s most likely the culprit.
  9. Test the Z-axis stepper driver and replace the mainboard if needed. To test the Z-axis stepper driver, remove the wire that goes into it and connect one of the motors that belong to a different axis. If the newly connected motor also doesn’t work, the stepper driver is the likely culprit.

Which Lubricant Should You Use for the Ender 3 (Pro/V2) Z Rod?

As the type of lubricant that you should use highly depends on the component that you intend to lubricate, making the correct choice is vital for the best results, and using a lubricant that isn’t suitable can cause more harm than good.

Dry film PTFE (Teflon) lubricant is the best option for lubricating your Ender 3’s Z rod (Z-axis lead screw), as it is pretty straightforward to apply (comes in a spray can that you can use directly) and does not leave any residue behind other than some dry powder that you won’t really need to remove.

If you can’t find any dry film PTFE lubricant, lithium grease is another alternative that would do the job, but unfortunately, unlike dry film PTFE lubricant, lithium grease can get pretty messy during the application process and eventually collects dust and dirt that you will need to clean.

Wrapping Up

As the issue of your Ender 3’s Z-axis failing to move is both a critical one that entirely prevents the printer from operating and a complex one at the same time due to the many possibilities involved, there is no denying that finding and applying the correct solution can be a long and arduous journey.

To quickly recap, mechanical and electrical issues, such as eccentric nuts that are too tight, a Z-axis lead screw that is unable to move, and general problems related to the wiring, endstop, mainboard, and motor are the primary causes behind your Ender 3’s Z-axis failing to move, with the firmware also being capable of creating such a situation in rare cases.

Since the majority of the issues are related to oversights that can easily be corrected when spotted, we highly recommend taking your time and going through each potential problem carefully before moving on to the next one to eliminate that possibility and narrow the list down one step at a time.

Happy printing!