Ender 3 (Pro & V2 & Neo & S1) Z-Axis Binding – Causes & Fixes

Z-axis binding is a common problem that you can face on your Ender 3, which is even more likely to occur right after you set your Ender 3 up for the first time, where the Z-axis lead screw is unable to move smoothly as the Z-axis stepper motor turns it, effectively creating a scenario where the Z-axis moves less than what’s intended, or sometimes, doesn’t move at all.

In this guide, we will discuss the factors that can contribute to the occurrence of the Z-axis binding problem on your Ender 3, take you through the possible solutions that will help you resolve the issue as swiftly as possible, and look at some of the signs that may indicate your Ender 3 is suffering from Z-axis binding.

Ender 3 (Pro & V2 & Neo & S1) Z-Axis Binding – Causes & Fixes

While Z-axis binding is a pretty straightforward issue to troubleshoot, as the majority of the problem takes place around the Z-axis coupler, the Z-axis lead screw, and the Z-axis stepper motor, there’s more than a single point of failure that can lead to the problem you’re experiencing, which makes it necessary to go through all the possibilities to find where the issue resides.

Extruder Mount Z-Axis Coupler Screws Too Tight

One of the primary factors that can lead to the Z-axis binding issue you’re experiencing on your Ender 3 is the coupler screws of the Z-axis extruder mount being way too tight, which leads to the coupler directly restricting the movement of the lead screw by gripping it to the point where it can’t turn anymore.

ender 3 extruder mount z axis coupler screws


To find these screws as conveniently as possible, start by locating the extruder on your Ender 3, then the extruder mount, which is the plastic piece that holds both the lead screw and the extruder together, and finally, the part of the lead screw that’s in contact with the extruder mount, which will lead you to see the two screws positioned to the left and the right of the lead screw on the extruder mount.

Once you have found the two screws, start by fully tightening both screws by using the 2 mm (the second smallest one in the set) hex key that ships with your Ender 3; follow that up by loosening each screw 1.5 to 2 full turns, and finally, try to move the Z-axis again by either using G-code commands or the LCD controller of your 3D printer to see whether the Z-axis binding issue still continues.

ender 3 2 mm hex key


In the case where the binding issue persists, our recommendation would be to repeat the cycle of loosening the screws slightly (less than a quarter turn at a time) and testing the Z-axis movement a couple more times to practically ensure that it’s impossible for them to be too tight anymore before moving on to the following solution, as we can effectively guarantee that the problem resides elsewhere in such a case.

Don’t forget to fully re-tighten and loosen the screws by 1.5 to 2 turns once you’re finished with testing to ensure that they don’t end up staying way too loose as you’re going through the following solutions!

On the other hand, if loosening the Z-axis coupler screws solved the problem in your case, ensure that you bring the screws to a point where they’re as tight as possible without causing the binding problem by making minor adjustments and testing the Z-axis movement, as screws that are too loose will lead to another problem where the lead screw ends up missing steps (rotates less than intended due to the movement from the stepper motor not being transmitted accurately) due to the coupler not having the necessary grip on it.

Z-Axis Eccentric Nut Too Tight

Another commonly encountered problem that can lead to the Z-axis binding issue you’re experiencing on your Ender 3 is the eccentric nut responsible for moving the Z-axis (X-gantry) being way too tight, which effectively creates a situation where the resistance from the V-rollers as a result of them not being able to turn smoothly due to the tightness overpower the movement of the lead screw.

ender 3 z axis eccentric nut


To find the Z-axis eccentric nut on your Ender 3, start by looking at the area between the X-gantry and the extruder, where you will see one of the two V-slot rollers (the other roller is on the opposite side but doesn’t have an eccentric nut) that allow the gantry to move up and down as the Z-axis stepper turns the lead screw, and between the V-slot roller and the extruder mount, you will find the eccentric nut that determines how tightly the V-slot roller will grip the frame.

Once you have eyes on the Z-axis eccentric nut, grab the double-sided wrench that came with your Ender 3, use its larger end to loosen the eccentric nut very slightly, try moving the Z-axis by either using the LCD controller of your Ender 3 or G-code commands and observe the movement to find out whether the Z-axis binding issue persists.

ender 3 eccentric nut wrench


In the case where you’re still experiencing Z-axis binding on your Ender 3, our recommendation would be to keep loosening the eccentric nut in small increments and making Z-axis movements to test whether the binding issue persists and to keep repeating this process until the V-slot roller becomes loose enough to the point where it physically cannot contribute to the issue as it will barely have a grip on the frame anymore.

On the other hand, if loosening the Z-axis eccentric nut solved the Z-axis binding issue for you, make sure to re-tighten the nut to the point where the V-slot roller doesn’t wobble without reintroducing the binding problem again by making minor adjustments and testing the Z-axis movement, as overly loosening the eccentric nut will cause the X-gantry to shake during movement due to the V-slot roller not having tight enough of a grip on the frame where it moves, which then will introduce a variety of print quality issues.

Misaligned Z-Axis Lead Screw

A misaligned Z-axis lead screw, where the lead screw ends up being completely out of alignment with the coupler located on the extruder mount, is a widespread issue that we can perhaps consider to be the most common cause of the Z-axis binding problem you’re experiencing with your Ender 3, with the lead screw becoming unable to rotate correctly due to it becoming angled instead of going straight up from the motor.

ender 3 misaligned z-axis lead screw diagram


To find out whether this is what’s causing the Z-axis binding problem for you, the first step we recommend taking is to look at the lead screw from up close and find out whether the part between the Z-axis coupler and the extruder mount coupler looks angled, preferably the help of a tool such as a bubble level if you have one at hand, as it will produce a more reliable result.

On the other hand, if you suspect that the Z-axis lead screw is misaligned but can’t tell directly by looking at it due to the misalignment not being too severe, you will need to detach it from your Ender 3 temporarily to apply a method that will produce more definitive results on finding out whether there is a misalignment or not.

For this process, the first step you will need to take is to tighten the Z-axis coupler screws located on the extruder mount until the coupler is able to grip the lead screw without any looseness.

ender 3 extruder mount z axis coupler screws


Afterward, you will need to loosen the top screw on the Z-axis coupler to release the lead screw from the coupler, which will make it possible to separate the lead screw from the Z-axis stepper motor.

ender 3 z axis coupler


Once that’s done, the next step you will need to take is to remove the screws responsible for attaching the Z-axis stepper motor to the frame of your Ender 3, which will effectively bring the motor to its position where it’s not pushed up against the frame by the screws.

ender 3 z axis motor frame screws


Finally, the last step you will need to take for this test is to pull the lead screw up until the tip of the screw has a decent amount of distance from the Z-axis motor, let it drop straight down (which should be the case if you have tightened the extruder mount coupler screws as mentioned earlier), and see where it lands.

In a scenario where the lead screw falls directly into the Z-axis coupler without any intervention required on your part, we can say that a misaligned Z-axis lead screw is not what’s causing the Z-axis binding problem for you, as this shows us that the lead screw and the motor are aligned correctly for the lead screw to go into the coupler when it falls straight down.

On the other hand, if the lead screw and the coupler don’t connect in this case, with it becoming necessary to pull the motor away from the frame for the coupler and the lead screw to line up as intended, a misaligned Z-axis lead screw is indeed the problem you’re experiencing, which is a factory defect that affects many Ender 3 printers.

In this case, a quick and convenient solution you can apply to resolve the problem is to use your Ender 3 to print a piece known as a Z-motor spacer, which effectively sits between the frame and the Z-axis motor to create some extra distance in between to get the lead screw to line up with the Z-axis coupler as intended, even with the motor fully pushed up against the frame with the tightened screws.

ender 3 motor spacer alignment fix


Dirty / Unlubricated Z-Axis Lead Screw

The usage of a dirty or unlubricated lead screw is yet another commonly encountered problem that can easily lead to the Z-axis binding problem your Ender 3 is having, as both lack of lubrication and the gathering of dust and dirt on the lead screw will easily prevent it from performing smooth rotations, which will present itself in the form of binding where the Z-axis isn’t able to move as intended.

ender 3 lead screw attached to printer


As there’s no easy way to find out whether this is what’s causing the problem in your case, our recommendation at this point (considering you’ve been through the previous solutions already) would be to remove the lead screw from your Ender 3 (you can follow the steps in the earlier section), clean it thoroughly, lubricate it, and put it back in its place, which will allow you to completely rule the possibility of a dirty or unlubricated lead screw, and also ensure that the lead screw stays well-maintained even if there were no issues.

When it comes to cleaning the lead screw in a convenient and reliable manner, our recommendation would be to start out by letting it stay in a container of isopropyl alcohol for a few hours, followed by a thorough brushing to get all the dirt out with the help of either a brass brush or a regular toothbrush if you don’t have access to a brass brush right now, which should ensure that your lead screw is good as new.

Additionally, while you already have the lead screw removed, it should also be a good idea to clean both the extruder mount and the Z-axis couplers with some degreaser to ensure there’s nothing there that can contribute to the binding issue you’re experiencing, as the insides of these parts can also get dirty over time.

Once you ensure that the lead screw is fully clean, the next step you will need to take is to lubricate the lead screw (remember to wear gloves to avoid contaminating the lead screw during and after lubrication!) with either PTFE grease, lithium grease, or silicone grease, which will allow it to rotate more smoothly and reduce wear and tear on both the lead screw itself and the couplers it’s connected to.

With the lead screw ready to go, the last step you will need to take is to attach it back to your Ender 3, which should hopefully solve the Z-axis binding problem you’ve been experiencing.

Damaged / Bent / Worn Out Z-Axis Lead Screw

If you haven’t been able to solve the Z-axis binding problem through the solutions we have discussed so far, there’s a good chance that the lead screw itself is either damaged, bent, or worn out to the point where it’s unable to rotate smoothly anymore, which isn’t exactly surprising considering that the material quality isn’t too high, and especially likely if you’ve been using your Ender 3 for a while now.

ender 3 damaged lead screw
Source: Natural Number Guy @ Stack Exchange (CC BY-NC-SA 4.0)

In this case, the first step we recommend taking is to find out whether the lead screw is bent or not by rolling it on a straight surface, which is a pretty straightforward and reliable method that will immediately show you whether bending is indeed the culprit behind the Z-axis binding problem you’re experiencing, as the lead screw will wobble as you’re rolling it if it’s bent instead of rotating smoothly.

Provided that the lead screw is straight, the next step is to find out whether there are signs of damage or wear & tear on it through careful observation, as a defect that even affects a small area on the lead screw can create the binding issue problem you’re experiencing if it’s severe enough to prevent it from rotating in the coupler.

That said, considering it may not be easy to reliably locate defects and signs of wear and tear on the lead screw in all cases, especially if you aren’t familiar with how an undamaged lead screw looks or don’t have a spare one to compare with, our recommendation would be to replace the lead screw with a new one and rule the possibility of damage or wear & tear completely, and even more so if you have tried every other solution and seem to be running out of options in solving the problem at hand.

What Are the Signs of Ender 3 (Pro & V2 & Neo & S1) Z-Axis Binding?

If you are unsure whether your Ender 3 has the Z-axis binding problem and would like to confirm that this is indeed the issue you’re experiencing before diving into the troubleshooting process, comparing the signs you’re observing to the common signs that the Z-axis binding problem would produce, which we have listed below, should be helpful.

The most noticeable sign of the Z-axis binding problem, in most cases, is the loud grinding sounds that come from the lead screw and the Z-axis coupler as the stepper motor tries to rotate the lead screw, usually also combined with vibrations around this area due to the lead screw resisting the movement provided by the stepper motor.

On the other hand, when it comes to the effects of Z-axis binding on the printed object, the main issue you will notice, usually in more severe cases where the Z-axis movement is limited heavily due to the binding, is dimensional inaccuracies on the Z-axis, with the printed object usually looking shorter and “squished” due to your Ender 3 being unable to make the correct Z axis movements.

3d printing squished layers example
Source: Dennis Wurster @ Stack Exchange (CC BY-NC-SA 4.0)

Alongside these two primary symptoms that should be relatively straightforward to observe, you can also come across signs such as clicking sounds from the Z-axis stepper motor, the lead screw completely locking up when trying to move above or below a particular height, and even complete print failure due to failed Z movement, which is worth keeping in mind when determining whether Z-axis binding is the problem you’re facing.

Conclusion

As Z-axis binding is a problem that will severely affect print quality to the point where prints will most likely end up failing or the printed part ending up unusable, we highly recommend taking the necessary steps to fix this issue as soon as you notice that something is wrong before you move forward with another print.

Fortunately, even though it is a critical one that you should be attending to as soon as possible, solving the Z-axis binding problem of your Ender 3 shouldn’t prove to be way too challenging by any means, as the possible culprits behind the issue are pretty straightforward to locate, and the corresponding solutions are relatively easy to apply.