<p>I'm new to 3D printing, so please forgive a noob question. I've tried a few different settings in Cura slicer and the walls of my prints consistently have gaps between them. I checked all the suggestions in <a href="https://3dprinting.stackexchange.com/questions/10276/how-to-fix-wall-separation-in-3d-prints-gaps-in-between-wall-perimeters">How to fix wall separation in 3D prints (gaps in between wall perimeters)?</a> and I do not see an improvement. Printing plain PLA at 220 °C on an Ender 3 Neo with a direct drive and 0.4 mm nozzle.</p>
<p><a href="https://i.sstatic.net/LhbZuY8d.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/LhbZuY8d.png" alt="enter image description here" /></a></p>
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<p>From the underside, the bottom layer is nicely merged</p>
<p>The result looks fine externally, but the gap between the walls looks huge (relatively speaking)</p>
<p><a href="https://i.sstatic.net/AJMOY7c8.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/AJMOY7c8.png" alt="enter image description here" /></a></p>
<p>Here are my slicer settings. I increased the line width, infill overlap percentage, and wall line width. I slowed down the wall speed. and I get the same result. From what I've read, this is under-extrusion but I don't know what else to try.</p>
<p><a href="https://i.sstatic.net/tr2c6C5y.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/tr2c6C5y.png" alt="enter image description here" /></a></p>
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<p>I watched a video about tuning the flow rate using a 20 mm cube and measuring the wall thickness. This confirmed the under-extrusion. I increased the flow rate on the Ender 3 settings, which definitely improved things. I also tried increasing the <strong>Wall Flow</strong> rate in the slicer. This worked too.</p>
<p>I went from 100% to 127% based on the ratio of the <em>actual</em> wall thickness to the <em>expected</em> wall thickness</p>
<p>I'd like to understand why only the walls are under-extruding</p>

CC BY-SA 4.0
2024-09-30T17:55:00.580Z
Side note, your initial layer height shouldn't surpass about 75 % of the nozzle width. Yes, you are experiencing underextrusion. So, somehow, not enough filament is reaching the nozzle. Check your extruder if enough pressure is exerted on the filament that it isn't skipping. Also check if you command 100 mm to be extruded, it actually extrudes 100 mm.
0scar
CC BY-SA 4.0
2024-09-30T20:34:55.337Z
Thanks @Oscar. Maybe this is a dumb question: I found the gcode to extrude 100mm `G1 E100 F150` but would that do 100mm of filament or 100mm from the nozzle? Everything else in my prints seems to be fine, so in my mind an extruder issue would affect everything, not just the walls
Adam Hey
CC BY-SA 4.0
2024-09-30T20:36:37.690Z
Just found this resource, which I'll try https://mattshub.com/blogs/blog/extruder-calibration
Adam Hey
CC BY-SA 4.0
2024-09-30T20:43:49.980Z
`G1 E100` will do 100 mm of your filament, in your case the 1.75 mm diameter. It would be hard to measure the extruded length . You don't need to get far for a resource, [How do I calibrate the extruder of my printer?](https://3dprinting.stackexchange.com/questions/6483/how-do-i-calibrate-the-extruder-of-my-printer) can be used from this stack! Note that a bought printer with stock firmware shouldn't require such a calibration, if it does, you should really check your extruder, it might be slipping filament on extrusion.
0scar
CC BY-SA 4.0
2024-10-02T20:25:41.373Z
Thanks @Oscar I updated the `Flow` setting in the Ender 3 while it was printing and the issue seems to be solved, but I suspect that's not the best way to "fix" it because it will surely affect all elements of the print. I tried slicing with the Bambu Labs slicer and got the same result before changing the flow setting, so it seems more like a printer issue than config in the slicers. I'm in the middle of a large print, so I'll try that calibration when it's done. Thanks again
Adam Hey
CC BY-SA 4.0
2024-10-19T01:02:56.863Z
I see 0.6 mm wall thickness. I wonder if you actually have a (very common) 0.4 mm nozzle.
Joel Coehoorn
<creality-ender-3><ultimaker-cura>
Why am I getting gaps between my walls?
Adam Hey
# Why am I getting gaps between my walls?

(Asked by: username_0 on 2024-09-30)

I'm new to 3D printing, so please forgive a noob question. I've tried a few different settings in Cura slicer and the walls of my prints consistently have gaps between them. I checked all the suggestions in [How to fix wall separation in 3D prints (gaps in between wall perimeters)?](https://3dprinting.stackexchange.com/questions/10276/how-to-fix-wall-separation-in-3d-prints-gaps-in-between-wall-perimeters) and I do not see an improvement. Printing plain PLA at 220 °C on an Ender 3 Neo with a direct drive and 0.4 mm nozzle.

[![enter image description here](https://i.sstatic.net/LhbZuY8d.png)](https://i.sstatic.net/LhbZuY8d.png)

[![enter image description here](https://i.sstatic.net/o502kDA4.png)](https://i.sstatic.net/o502kDA4.png)

From the underside, the bottom layer is nicely merged

The result looks fine externally, but the gap between the walls looks huge (relatively speaking)

[![enter image description here](https://i.sstatic.net/AJMOY7c8.png)](https://i.sstatic.net/AJMOY7c8.png)

Here are my slicer settings. I increased the line width, infill overlap percentage, and wall line width. I slowed down the wall speed. and I get the same result. From what I've read, this is under-extrusion but I don't know what else to try.

[![enter image description here](https://i.sstatic.net/tr2c6C5y.png)](https://i.sstatic.net/tr2c6C5y.png)

[![enter image description here](https://i.sstatic.net/OolZae18.png)](https://i.sstatic.net/OolZae18.png)

[![enter image description here](https://i.sstatic.net/82A3zyQT.png)](https://i.sstatic.net/82A3zyQT.png)

I watched a video about tuning the flow rate using a 20 mm cube and measuring the wall thickness. This confirmed the under-extrusion. I increased the flow rate on the Ender 3 settings, which definitely improved things. I also tried increasing the **Wall Flow** rate in the slicer. This worked too.

I went from 100% to 127% based on the ratio of the *actual* wall thickness to the *expected* wall thickness

I'd like to understand why only the walls are under-extruding

**Tags:** creality-ender-3, ultimaker-cura
> **Comments:**
> **username_1**: Side note, your initial layer height shouldn't surpass about 75 % of the nozzle width. Yes, you are experiencing underextrusion. So, somehow, not enough filament is reaching the nozzle. Check your extruder if enough pressure is exerted on the filament that it isn't skipping. Also check if you command 100 mm to be extruded, it actually extrudes 100 mm.  
> **username_0**: Thanks @Oscar. Maybe this is a dumb question: I found the gcode to extrude 100mm `G1 E100 F150` but would that do 100mm of filament or 100mm from the nozzle? Everything else in my prints seems to be fine, so in my mind an extruder issue would affect everything, not just the walls  
> **username_0**: Just found this resource, which I'll try https://mattshub.com/blogs/blog/extruder-calibration  
> **username_1**: `G1 E100` will do 100 mm of your filament, in your case the 1.75 mm diameter. It would be hard to measure the extruded length . You don't need to get far for a resource, [How do I calibrate the extruder of my printer?](https://3dprinting.stackexchange.com/questions/6483/how-do-i-calibrate-the-extruder-of-my-printer) can be used from this stack! Note that a bought printer with stock firmware shouldn't require such a calibration, if it does, you should really check your extruder, it might be slipping filament on extrusion.  
> **username_0**: Thanks @Oscar I updated the `Flow` setting in the Ender 3 while it was printing and the issue seems to be solved, but I suspect that's not the best way to "fix" it because it will surely affect all elements of the print. I tried slicing with the Bambu Labs slicer and got the same result before changing the flow setting, so it seems more like a printer issue than config in the slicers. I'm in the middle of a large print, so I'll try that calibration when it's done. Thanks again  
> **username_2**: I see 0.6 mm wall thickness. I wonder if you actually have a (very common) 0.4 mm nozzle.  

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## 0 answers

