<p>It looks like you might have some slack in your PTFE tube. At the end of the printed line, the extruder tries to retract to prevent the builtup pressure excaping from the nozzle. If there is slack in the line, the pressure stays too high and material exits at the end of the line.</p>
<p>Can you take out the filament and feel if the PTFE tube is snuggly fixed to the extruder and the toolhead?</p>
<p>As a test: can you see if the extruder retracts by looking at the extruder wheel? Do you see the filament coming out of the extruder in the opposite direction?</p>

CC BY-SA 4.0
2024-12-12T09:45:10.803Z
2024-12-12T09:45:10.803Z
Hacky
<p>I suspect that you have a negative value filled in for <strong>Retraction</strong> in Cura.</p>
<p>Retraction is implicitly negative, i.e. the setting is directing the printer to &quot;retract by this (positive) amount&quot;; by entering a negative amount for Retraction in the slicer, you're telling it to extrude <em><strong>more</strong></em> filament at the end of a line, which would explain the extra extrusion and could cause the stepper/mechanical flexing noises you've described if the amount is large enough to cause back-pressure.</p>
<p>Simplify3D and PrusaSlicer either prevent entry of or ignore a negative Retraction value, but I've confirmed that Cura 5.7.2 permits a negative Retraction setting and that the resulting G-code file reflects the &quot;negative retraction&quot; (extra extrusion) in the extrusion moves.</p>

CC BY-SA 4.0
2024-07-14T23:07:25.840Z
Sadly thats not it. Here are my retraction settings:      Enable retraction, Retraction distance = 5.00mm , speed = 45.00mm/s
Useer_1782
CC BY-SA 4.0
2024-07-15T11:15:26.123Z
Thanks for confirming that. Is there a way you can share a small G-code file that exhibits the problem?
Tuill
CC BY-SA 4.0
2024-07-15T19:07:14.813Z
sure here you go ( the code is to long to put here, so here is a link: https://anotepad.com/notes/tfejchwc
Useer_1782
CC BY-SA 4.0
2024-07-16T02:28:39.323Z
From my naive look I don't see what I had I suspected, I can indeed see the extruder performing retraction before the next layer is started. I do see what looks like the tool path reversing XY directions before the Z upward move, which I wouldn't expect, but without knowing what the object is it could be an infill or something else with an explanation.
Tuill
CC BY-SA 4.0
2024-07-14T21:28:06.567Z
2024-07-14T21:28:06.567Z
Tuill
<p>Don't forget to tune Linear Advance but <a href="https://www.reddit.com/r/3Dprinting/comments/zl9bcv/linear_advance_on_creality_422_board_ender_3_v2/" rel="nofollow noreferrer">you need</a> the latest firmware with Marlin 2.1, I think</p>

CC BY-SA 4.0
2024-12-17T08:08:14.057Z
2024-12-17T08:08:14.057Z
FarO
<p>My Ender 3 v2 pushes extra filament for about half a second at the end of each layer, which makes it extrude a tiny bit of filament. After more layers, that bump becomes bigger and bigger. I've tried: Slowing and speeding up the nozzle, different SD cards, printing via USB, turning off/on retract at layer change, I tried printing on different spots of the bed, and I tried printing with different temperatures of the nozzle and bed. I have a BLTouch probe and have leveled my bed multiple times with the built-in feature, and with paper.</p>
<p>Also if it helps, my extruder makes an oinking noise every time it retracts.</p>
<p><a href="https://i.sstatic.net/2fQoiy7M.png" rel="nofollow noreferrer" title="Graphic of what is happening (a printed line with a blob at the end) and what is wanted to happen (a line printed straight with no blobs at either end)"><img src="https://i.sstatic.net/2fQoiy7M.png" alt="Graphic of what is happening (a printed line with a blob at the end) and what is wanted to happen (a line printed straight with no blobs at either end)" title="Graphic of what is happening (a printed line with a blob at the end) and what is wanted to happen (a line printed straight with no blobs at either end)" /></a></p>

CC BY-SA 4.0
2024-07-14T20:56:20.680Z
What are you using for a slicer? I had wondered if you had a negative value filled in for the retraction amount. Retraction is implicitly negative, so the setting is saying "retract by this (positive) amount", but Simplify3D (at least v4) won't allow a negative retraction value, and PrusaSlicer seems to treat a negative value the same as zero (perform no retraction). Though I can't reproduce a "negative retraction" with the slicers that I have, it would explain the behavior seen: extra extrusion toward the ends of lines, and noise from the extruder stepper as it tried to overextrude.
Tuill
CC BY-SA 4.0
2024-07-15T21:04:23.533Z
Are you using linear advance?
0scar
<creality-ender-3><print-quality><troubleshooting>
Why is my printer overextruding at one end of one layer?
Useer_1782
# Why is my printer overextruding at one end of one layer?

(Asked by: username_0 on 2024-07-14)

My Ender 3 v2 pushes extra filament for about half a second at the end of each layer, which makes it extrude a tiny bit of filament. After more layers, that bump becomes bigger and bigger. I've tried: Slowing and speeding up the nozzle, different SD cards, printing via USB, turning off/on retract at layer change, I tried printing on different spots of the bed, and I tried printing with different temperatures of the nozzle and bed. I have a BLTouch probe and have leveled my bed multiple times with the built-in feature, and with paper.

Also if it helps, my extruder makes an oinking noise every time it retracts.

[![Graphic of what is happening (a printed line with a blob at the end) and what is wanted to happen (a line printed straight with no blobs at either end)](https://i.sstatic.net/2fQoiy7M.png "Graphic of what is happening (a printed line with a blob at the end) and what is wanted to happen (a line printed straight with no blobs at either end)")](https://i.sstatic.net/2fQoiy7M.png "Graphic of what is happening (a printed line with a blob at the end) and what is wanted to happen (a line printed straight with no blobs at either end)")

**Tags:** creality-ender-3, print-quality, troubleshooting
> **Comments:**
> **username_1**: What are you using for a slicer? I had wondered if you had a negative value filled in for the retraction amount. Retraction is implicitly negative, so the setting is saying "retract by this (positive) amount", but Simplify3D (at least v4) won't allow a negative retraction value, and PrusaSlicer seems to treat a negative value the same as zero (perform no retraction). Though I can't reproduce a "negative retraction" with the slicers that I have, it would explain the behavior seen: extra extrusion toward the ends of lines, and noise from the extruder stepper as it tried to overextrude.  
> **username_2**: Are you using linear advance?  

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## 3 answers

### Answer by username_3 on 2024-12-12. Score: 0

It looks like you might have some slack in your PTFE tube. At the end of the printed line, the extruder tries to retract to prevent the builtup pressure excaping from the nozzle. If there is slack in the line, the pressure stays too high and material exits at the end of the line.

Can you take out the filament and feel if the PTFE tube is snuggly fixed to the extruder and the toolhead?

As a test: can you see if the extruder retracts by looking at the extruder wheel? Do you see the filament coming out of the extruder in the opposite direction?


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### Answer by username_1 on 2024-07-14. Score: 0

I suspect that you have a negative value filled in for **Retraction** in Cura.

Retraction is implicitly negative, i.e. the setting is directing the printer to "retract by this (positive) amount"; by entering a negative amount for Retraction in the slicer, you're telling it to extrude ***more*** filament at the end of a line, which would explain the extra extrusion and could cause the stepper/mechanical flexing noises you've described if the amount is large enough to cause back-pressure.

Simplify3D and PrusaSlicer either prevent entry of or ignore a negative Retraction value, but I've confirmed that Cura 5.7.2 permits a negative Retraction setting and that the resulting G-code file reflects the "negative retraction" (extra extrusion) in the extrusion moves.

> **Comments:**
> **username_0**: Sadly thats not it. Here are my retraction settings:      Enable retraction, Retraction distance = 5.00mm , speed = 45.00mm/s  
> **username_1**: Thanks for confirming that. Is there a way you can share a small G-code file that exhibits the problem?  
> **username_0**: sure here you go ( the code is to long to put here, so here is a link: https://anotepad.com/notes/tfejchwc  
> **username_1**: From my naive look I don't see what I had I suspected, I can indeed see the extruder performing retraction before the next layer is started. I do see what looks like the tool path reversing XY directions before the Z upward move, which I wouldn't expect, but without knowing what the object is it could be an infill or something else with an explanation.  

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### Answer by username_4 on 2024-12-17. Score: -1

Don't forget to tune Linear Advance but [you need](https://www.reddit.com/r/3Dprinting/comments/zl9bcv/linear_advance_on_creality_422_board_ender_3_v2/) the latest firmware with Marlin 2.1, I think


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