<h2>Triangles?!</h2>
<p>First of all, the triangles on the STL are not a problem - they are just how STL is defined: a mesh of triangles. you can't save anything but triangles in STL, so let's not bother with that item but the actual elephant in the room: the print.</p>
<h1>Underextrusion</h1>
<h2>Step 1: proper settings</h2>
<p>It shows signs of underextrusion. And I can exactly tell you where part of it comes from: You have set the line width to <em>below</em> the nozzle width. However, the line width should be best 10% <em>larger</em> than the nozzle. <strong>All</strong> of these lines should read between 0.4 to (as I have set it) 0.45 mm:</p>
<p><a href="https://i.sstatic.net/MLa2e.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/MLa2e.png" alt="enter image description here" /></a></p>
<p>With a 10% wider line planned into, it is not necessary to have an extra initial layer line width of more than 100 %, but it can help in adhesion.</p>
<h2>Step 2: Other issues?!</h2>
<p>There might be other issues at work, though they will show up after setting the width much better. The following two strike me as most likely if the problem persists with the now considerable increased flow:</p>
<ul>
<li>The retraction and/or retraction speed might be set too high.</li>
<li>mechanical issues of the extruder system, for example, worn gears or uneven pressure against the gear due to damaged parts.</li>
</ul>

CC BY-SA 4.0
2020-03-04T09:16:57.460Z
I've done the settings by your recomendation but when i slice it it still shows the inproper infill of the walls –
But when i increase the layer hight to 0.25mm and slice it it looks fine.
Something wierd is going on. Because when I then change it back to 0.2mm layer hight it looks fine. Must cache something. So it seems that your setting will work.

Many thanks!
Tobbe
CC BY-SA 4.0
2020-03-04T09:38:50.507Z
@Tobbe note that you can set "Initial layer width" to 100% too.
Trish
CC BY-SA 4.0
2020-03-04T13:38:18.413Z
This looks more like localized underextrusion due to loss of material. Line widths down to 0.35 or even 0.3 are unconventional but should be okay. I've even printed 0.2 mm lines using a standard 0.4 mm nozzle and didn't have any problems with extrusion consistency.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2020-03-04T19:17:16.633Z
@R..GitHubSTOPHELPINGICE Possibly... Retraction!
Trish
CC BY-SA 4.0
2020-03-05T00:53:57.930Z
@Trish: Yeah that would be my first guess, but you can also end up with loss of material from combing over infill, or can have underextrusion due to coasting or other weird slicer options.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2020-03-05T15:11:23.143Z
The 0.35 mm is the default width for Ultimaker machines and works perfectly, I've printed kilometers of filament with the default settings without a problem.
0scar
CC BY-SA 4.0
2020-03-05T15:55:49.063Z
Maybe drop the layer height to 0.18 .  I've seen claims that multiples of the default 0.06 work better.  Or maybe not  :-)
Carl Witthoft
CC BY-SA 4.0
2020-03-04T08:54:10.057Z
2020-03-05T11:25:24.803Z
2020-06-18T08:29:41.667Z
Trish
<p>I'm using Cura 4.5.0 and an Ultimaker S5</p>

<p>The walls in my model are coming out not solid. I don't have a clue why.</p>

<p><a href="https://i.sstatic.net/TNETT.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/TNETT.jpg" alt="enter image description here"></a></p>

<p><a href="https://i.sstatic.net/rAcCs.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/rAcCs.png" alt="enter image description here"></a></p>

<p>When I open the STL in Sketchup it has all these weird lines. I don't know how they got there and I don't know how to get rid of them.</p>

<p><a href="https://i.sstatic.net/1feCe.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/1feCe.png" alt="enter image description here"></a></p>

CC BY-SA 4.0
2020-03-04T08:22:31.967Z
The lines are not a problem, they come from being STL - which is all triangles.
Trish
CC BY-SA 4.0
2020-03-04T08:30:03.040Z
What is the width of the walls, what is your nozzle, what is your line widths?
Trish
CC BY-SA 4.0
2020-03-04T08:33:24.923Z
Nozzle 0.4, walls 1.75mm. Running Cura on recommended 0.2 line
Tobbe
CC BY-SA 4.0
2020-03-04T19:17:28.560Z
What's the retraction distance?
Trish
<ultimaker-cura>
Uneven walls, not solid
Tobbe
# Uneven walls, not solid

(Asked by: username_0 on 2020-03-04)

I'm using Cura 4.5.0 and an Ultimaker S5

The walls in my model are coming out not solid. I don't have a clue why.

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

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

When I open the STL in Sketchup it has all these weird lines. I don't know how they got there and I don't know how to get rid of them.

[![enter image description here](https://i.sstatic.net/1feCe.png)](https://i.sstatic.net/1feCe.png)

**Tags:** ultimaker-cura
> **Comments:**
> **username_1**: The lines are not a problem, they come from being STL - which is all triangles.  
> **username_1**: What is the width of the walls, what is your nozzle, what is your line widths?  
> **username_0**: Nozzle 0.4, walls 1.75mm. Running Cura on recommended 0.2 line  
> **username_1**: What's the retraction distance?  

---

## 1 answers

### Answer by username_1 on 2020-03-04. Score: 2 | Accepted answer

## Triangles?!

First of all, the triangles on the STL are not a problem - they are just how STL is defined: a mesh of triangles. you can't save anything but triangles in STL, so let's not bother with that item but the actual elephant in the room: the print.

# Underextrusion

## Step 1: proper settings

It shows signs of underextrusion. And I can exactly tell you where part of it comes from: You have set the line width to *below* the nozzle width. However, the line width should be best 10% *larger* than the nozzle. **All** of these lines should read between 0.4 to (as I have set it) 0.45 mm:

[![enter image description here](https://i.sstatic.net/MLa2e.png)](https://i.sstatic.net/MLa2e.png)

With a 10% wider line planned into, it is not necessary to have an extra initial layer line width of more than 100 %, but it can help in adhesion.

## Step 2: Other issues?!

There might be other issues at work, though they will show up after setting the width much better. The following two strike me as most likely if the problem persists with the now considerable increased flow:

* The retraction and/or retraction speed might be set too high.
* mechanical issues of the extruder system, for example, worn gears or uneven pressure against the gear due to damaged parts.

> **Comments:**
> **username_0**: I've done the settings by your recomendation but when i slice it it still shows the inproper infill of the walls – But when i increase the layer hight to 0.25mm and slice it it looks fine. Something wierd is going on. Because when I then change it back to 0.2mm layer hight it looks fine. Must cache something. So it seems that your setting will work.  Many thanks!  
> **username_1**: @Tobbe note that you can set "Initial layer width" to 100% too.  
> **username_2**: This looks more like localized underextrusion due to loss of material. Line widths down to 0.35 or even 0.3 are unconventional but should be okay. I've even printed 0.2 mm lines using a standard 0.4 mm nozzle and didn't have any problems with extrusion consistency.  
> **username_1**: @R..GitHubSTOPHELPINGICE Possibly... Retraction!  
> **username_2**: @Trish: Yeah that would be my first guess, but you can also end up with loss of material from combing over infill, or can have underextrusion due to coasting or other weird slicer options.  
> **username_3**: The 0.35 mm is the default width for Ultimaker machines and works perfectly, I've printed kilometers of filament with the default settings without a problem.  
> **username_4**: Maybe drop the layer height to 0.18 .  I've seen claims that multiples of the default 0.06 work better.  Or maybe not  :-)  

---

