<p>Can you send a link to a short video of the problem occuring? It might be because of multiple factors but we will be able to identify if there's a video of it.</p>

<p>Possible reasons:</p>

<ul>
<li><p>Z axis nut might be too tight. This would cause the nut to bind with the leadscrew and so the motor will not be able to lift the z-axis further while printing.</p></li>
<li><p>Not enough retraction. This would cause filament to ooze from the nozzle during travel moves and this filament would collide with the printed object, causing it to be knocked off. A possible solution for this would be to enable Z-hop in the slider, have the hop distance set to at least 1.5x the layer height you are currently printing with.</p></li>
<li><p>Too small of a contact area. This usually happens more often for tall prints. A solution would be to increase brim in the slicer settings (at least 10~15 lines) to increase the adhesion of the print and the bed.</p></li>
<li><p>Dirty nozzle. Old prints filament may be stuck on the outer face of the nozzle and might be catching onto the printed part while printing.</p></li>
</ul>

CC BY-SA 4.0
2019-12-24T07:15:50.440Z
2019-12-24T07:15:50.440Z
vbz
<p>I've had my Creality Ender 3 Pro since October 2019. It was running like a dream until about a month ago. The Z-axis started knocking prints off the plate during printing. I've changed mats and worked on adhesion issues. I've switched to a glass plate and triple checked that it is level. I checked to see if it was binding but honestly I couldn't tell. </p>

<p>I'm at a loss of what to do to troubleshoot and fix the issue. Any suggestions?</p>

<p>It homes fine and manual controls work fine with no issues.</p>

CC BY-SA 4.0
2019-12-23T20:03:14.633Z
Can you explain what you mean by the "Z axis knocking prints off"? What part actually collides or moves in a manner that's unexpected/erroneous?
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2019-12-25T19:02:05.403Z
can you check if your Potal (X-Axis) is orthogonal to the vertical bars? knocking it off is a known issiue.
Trish
CC BY-SA 4.0
2020-08-17T12:33:23.623Z
Did you ever find out what happened? Please add an answer if you did!
Jason
CC BY-SA 4.0
2021-01-09T10:18:12.877Z
did you get an answer to this? I'm having the same issue and the z axis keeps dropping during prints at regular intervals above a certain height, as if it can't hold itself up (all screws seem to be right, and there's no binding it just isn't holding itself at the right height)?
Willow
<creality-ender-3><troubleshooting>
Z-Axis raising and dropping substantially during print knocking print off
Krystal
# Z-Axis raising and dropping substantially during print knocking print off

(Asked by: username_0 on 2019-12-23)

I've had my Creality Ender 3 Pro since October 2019. It was running like a dream until about a month ago. The Z-axis started knocking prints off the plate during printing. I've changed mats and worked on adhesion issues. I've switched to a glass plate and triple checked that it is level. I checked to see if it was binding but honestly I couldn't tell.

I'm at a loss of what to do to troubleshoot and fix the issue. Any suggestions?

It homes fine and manual controls work fine with no issues.

**Tags:** creality-ender-3, troubleshooting

> **Comments:**
> **username_1**: Can you explain what you mean by the "Z axis knocking prints off"? What part actually collides or moves in a manner that's unexpected/erroneous?  
> **username_2**: can you check if your Potal (X-Axis) is orthogonal to the vertical bars? knocking it off is a known issiue.  
> **username_3**: Did you ever find out what happened? Please add an answer if you did!  
> **username_4**: did you get an answer to this? I'm having the same issue and the z axis keeps dropping during prints at regular intervals above a certain height, as if it can't hold itself up (all screws seem to be right, and there's no binding it just isn't holding itself at the right height)?  

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## 1 answers

### Answer by username_5 on 2019-12-24. Score: 2

Can you send a link to a short video of the problem occuring? It might be because of multiple factors but we will be able to identify if there's a video of it.

Possible reasons:

* Z axis nut might be too tight. This would cause the nut to bind with the leadscrew and so the motor will not be able to lift the z-axis further while printing.
* Not enough retraction. This would cause filament to ooze from the nozzle during travel moves and this filament would collide with the printed object, causing it to be knocked off. A possible solution for this would be to enable Z-hop in the slider, have the hop distance set to at least 1.5x the layer height you are currently printing with.
* Too small of a contact area. This usually happens more often for tall prints. A solution would be to increase brim in the slicer settings (at least 10~15 lines) to increase the adhesion of the print and the bed.
* Dirty nozzle. Old prints filament may be stuck on the outer face of the nozzle and might be catching onto the printed part while printing.


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