<p>My guess is your Z guides are not strictly parallel because there's no instruction how to install X guides correctly. When you install X guides, you can easily make horizontal distance between two Z-mounts either too small or too large, which puts extra stress on one of the Z motors. Move your extruder to home position, measure distance between bottom ends of Z threaded rods and between top ends, and try to adjust right Z-mount position on X guides so that these two distances become equal. Use hammer, but be accurate with plastic.</p>

CC BY-SA 3.0
2017-10-27T10:15:52.663Z
2017-10-27T10:15:52.663Z
ZuOverture
<p>Try winding the Z axis all the up and down a few times using the front panel controls. Does it still go out of alignment? Is it out of alignment at the top? Does it come back into alignment when you wind it back down?</p>

<p>The principle is: if you have a dodgy motor drive chip, or a mechanical fault, it will skip some steps on the way up and the two motors will be out of synch. Then, on the way back down, it will skip an (approximately equal) number of steps and the motors will return to something resembling similar places.</p>

CC BY-SA 3.0
2017-10-26T09:03:53.873Z
2017-10-26T09:03:53.873Z
KDM
<p>I've noticed that after my Anet A8 completes a print, the right hand Z mount ends up 1-2&nbsp;mm lower than the left, even though I make sure both the left and right hand Z mounts of the X-axis are at the same height before switching on the printer.</p>

<p>Does anyone know what the cause of this might be?</p>

<p>I'm guessing something is causing the right hand Z to skip steps. I can't see or hear any obvious mechanical issues. I checked all guide and threaded rods were straight before assembly.  </p>

<p>Could it be a faulty stepper or control electronics?</p>

CC BY-SA 3.0
2017-06-09T15:35:44.527Z
Try reuploading a firmware of your choice ( I prefer Marlin SkyNet3D version because it is preconfigured for the Anet A8).
Tooniis
CC BY-SA 3.0
2017-06-09T21:37:56.013Z
Duplicate of the other z-axis questions.
Sean Houlihane
CC BY-SA 3.0
2017-06-09T21:39:53.730Z
Possible duplicate of [Alignment of dual Z-axis steppers](https://3dprinting.stackexchange.com/questions/3059/alignment-of-dual-z-axis-steppers)
Sean Houlihane
CC BY-SA 3.0
2017-06-10T04:18:51.940Z
@SeanHoulihane - Hmmm, I thought this sounded familiar, when I reviewed it. However, your question is about the *possibility* of out-of-sync happening, and the answer offers no solution to this OP's issue (apart from the "levelling"). This question is looking for *the cause*, and, I guess, a definitive solution.
Greenonline
CC BY-SA 3.0
2017-06-10T09:01:49.007Z
This is one of the threads binding, due to bad alignment. Maybe I linked the wrong Q, there were 2 active when I experienced this.
Sean Houlihane
CC BY-SA 3.0
2017-06-10T09:50:34.617Z
this one https://3dprinting.stackexchange.com/questions/3065
Sean Houlihane
CC BY-SA 3.0
2017-06-12T11:19:02.517Z
It does sound like a binding issue.  Go into the control menu and manually drive the Z-axis up and down -- look for stickiness, 'bad' sounds, and so on.  Make sure the tops of both Z screws aren't hitting anything.
Carl Witthoft
CC BY-SA 3.0
2017-10-27T14:21:52.520Z
@Andrew Ebling, You have the Anet 8? I know its a little off topic but other than the issue you have how are you liking the printer?
Ljk2000
CC BY-SA 3.0
2017-10-30T17:15:37.927Z
@Ljk2000 with an upgraded 30A PSU, mosfets, re-soldered heat bed, drylin bearings and decent GT2 belts, it becomes a decent printer. I’m also looking at the AM8 metal frame upgrade.

It’s good enough to get me hooked on 3D printing, for sure.
Andrew Ebling
CC BY-SA 3.0
2017-10-30T17:54:14.337Z
@AndrewEbling With all those upgrades it sounds like you could have gotten a $200+ printer. I have heard some scary things about the power supply that comes with it though, Did the bearing improve the accuracy along with the GT2 belts?
Ljk2000
<z-axis><anet-a8>
Anet A8 right Z drops 2 mm during print
Andrew Ebling
# Anet A8 right Z drops 2 mm during print

(Asked by: username_0 on 2017-06-09)

I've noticed that after my Anet A8 completes a print, the right hand Z mount ends up 1-2 mm lower than the left, even though I make sure both the left and right hand Z mounts of the X-axis are at the same height before switching on the printer.

Does anyone know what the cause of this might be?

I'm guessing something is causing the right hand Z to skip steps. I can't see or hear any obvious mechanical issues. I checked all guide and threaded rods were straight before assembly.

Could it be a faulty stepper or control electronics?

**Tags:** z-axis, anet-a8

> **Comments:**
> **username_1**: Try reuploading a firmware of your choice ( I prefer Marlin SkyNet3D version because it is preconfigured for the Anet A8).  
> **username_2**: Duplicate of the other z-axis questions.  
> **username_2**: Possible duplicate of [Alignment of dual Z-axis steppers](https://3dprinting.stackexchange.com/questions/3059/alignment-of-dual-z-axis-steppers)  
> **username_3**: @username_2 - Hmmm, I thought this sounded familiar, when I reviewed it. However, your question is about the *possibility* of out-of-sync happening, and the answer offers no solution to this OP's issue (apart from the "levelling"). This question is looking for *the cause*, and, I guess, a definitive solution.  
> **username_2**: This is one of the threads binding, due to bad alignment. Maybe I linked the wrong Q, there were 2 active when I experienced this.  
> **username_2**: this one https://3dprinting.stackexchange.com/questions/3065  
> **username_4**: It does sound like a binding issue.  Go into the control menu and manually drive the Z-axis up and down -- look for stickiness, 'bad' sounds, and so on.  Make sure the tops of both Z screws aren't hitting anything.  
> **username_5**: @username_0, You have the Anet 8? I know its a little off topic but other than the issue you have how are you liking the printer?  
> **username_0**: @username_5 with an upgraded 30A PSU, mosfets, re-soldered heat bed, drylin bearings and decent GT2 belts, it becomes a decent printer. I’m also looking at the AM8 metal frame upgrade.  It’s good enough to get me hooked on 3D printing, for sure.  
> **username_5**: @username_0 With all those upgrades it sounds like you could have gotten a $200+ printer. I have heard some scary things about the power supply that comes with it though, Did the bearing improve the accuracy along with the GT2 belts?  

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## 2 answers

### Answer by username_6 on 2017-10-27. Score: 2

My guess is your Z guides are not strictly parallel because there's no instruction how to install X guides correctly. When you install X guides, you can easily make horizontal distance between two Z-mounts either too small or too large, which puts extra stress on one of the Z motors. Move your extruder to home position, measure distance between bottom ends of Z threaded rods and between top ends, and try to adjust right Z-mount position on X guides so that these two distances become equal. Use hammer, but be accurate with plastic.


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### Answer by username_7 on 2017-10-26. Score: 1

Try winding the Z axis all the up and down a few times using the front panel controls. Does it still go out of alignment? Is it out of alignment at the top? Does it come back into alignment when you wind it back down?

The principle is: if you have a dodgy motor drive chip, or a mechanical fault, it will skip some steps on the way up and the two motors will be out of synch. Then, on the way back down, it will skip an (approximately equal) number of steps and the motors will return to something resembling similar places.


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