<p>I had the same issue exporting from Sketchup to STL. I imported my STL to Tinkercad and then exported it again and it resolved my issue.</p>
<p>Tinkercad is a free and online tool.</p>

CC BY-SA 4.0
2021-04-28T17:43:11.073Z
2021-04-28T18:17:43.893Z
2021-04-28T18:17:43.893Z
Pablo Quintana
<p>It would appear that your model does not conform properly to STL standards. I base this conclusion on a couple of factors. When I loaded the model into Simplify3D slicer, it displayed fine, but when sliced, displayed nothing. Using the onboard repair feature, it presented the entire model as being composed of non-manifold surfaces.</p>

<p>Meshmixer's Analysis/Inspector feature also highlighted the entire model as flawed.</p>

<p>Another observation is that there is an extraordinary amount of facets/triangles/faces to this model. Nearly three-quarters of a million triangles for something that should be much simpler.</p>

<p>The most recent version of Prusa Slicer 2.0 presents an error message indicating that no layers were detected. This is peculiar indeed.</p>

<p>All of the above points to a problem with the source file or the software used to create it.</p>

<p>Please consider to add to your post the program you used or the source of the model.</p>

CC BY-SA 4.0
2019-08-22T17:09:46.963Z
I created the mesh using Pygmsh which saved it as a VTK file. I then converted it to STL using ParaView. I can provide the source later this evening after work but it does seem that my STL file is indeed abnormal and that I should probably use a canonical CAD program.
Gearoid Murphy
CC BY-SA 4.0
2019-08-22T17:44:53.537Z
From my brief bit of research, I see that Pygmsh is a facilitator for gmsh, which appears to be founded strongly in coding. To that end, consider to check out http://www.openscad.org for a scripting type 3d modeling program. Your cone might be three modules, maybe four at the most. Two cylinders (base and cone) and another cylinder subtracted from the union.
fred_dot_u
CC BY-SA 4.0
2019-08-23T15:06:05.407Z
OpenSCAD is perfect, so much easier than my previous approach!
Gearoid Murphy
CC BY-SA 4.0
2019-08-23T17:16:36.493Z
I'm happy to hear that you like it. It's my first attack program, unless the part/model is severely organic in shape.
fred_dot_u
CC BY-SA 4.0
2019-08-22T16:12:59.467Z
2019-08-22T16:12:59.467Z
fred_dot_u
<p>I'm trying to print a supporting base which will house the spindle for an electrostatic rotor. It's basically just a truncated cone with a hole down it's center to house the spindle.</p>

<p>For reasons that I cannot fathom, Ultimaker Cura keeps on adding an unrequested top/bottom layer (color-coded yellow in the screenshots) inside this hole, so instead of a single hollow cylinder of 10&nbsp;mm depth, the result is a hole only a few millimeters deep with another hollow cylinder behind it.</p>

<p>Here is the intended model, note the open space for the hole at the top.</p>

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

<p>Here is the inner view of the hole being printed as expected:</p>

<p><a href="https://i.sstatic.net/kXV5x.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/kXV5x.png" alt="enter image description here"></a></p>

<p>Finally, here is a layer view of the print a few millimeters from the final top layer with the unrequested top/bottom layer that covers the spindle hole:</p>

<p><a href="https://i.sstatic.net/Yd8mn.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Yd8mn.png" alt="enter image description here"></a></p>

<p>The STL file is on <a href="https://github.com/gearoid-murphy/3dprints/blob/master/spindle.stl" rel="nofollow noreferrer">Github</a> (with a built-in viewer).</p>

<p>Can anyone help me understand why this is happening?</p>

CC BY-SA 4.0
2019-08-22T16:23:56.037Z
Did you try to heal the stl in a program like MeshLab and slice the healed model?
Davo
CC BY-SA 4.0
2019-08-22T17:07:55.257Z
No, I created a VTK file using Pygmsh and then converted it to STL using ParaView
Gearoid Murphy
<ultimaker-cura><slicing><troubleshooting>
Ultimaker Cura is adding redundant top/bottom layers
Gearoid Murphy
# Ultimaker Cura is adding redundant top/bottom layers

(Asked by: username_0 on 2019-08-22)

I'm trying to print a supporting base which will house the spindle for an electrostatic rotor. It's basically just a truncated cone with a hole down it's center to house the spindle.

For reasons that I cannot fathom, Ultimaker Cura keeps on adding an unrequested top/bottom layer (color-coded yellow in the screenshots) inside this hole, so instead of a single hollow cylinder of 10 mm depth, the result is a hole only a few millimeters deep with another hollow cylinder behind it.

Here is the intended model, note the open space for the hole at the top.

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

Here is the inner view of the hole being printed as expected:

[![enter image description here](https://i.sstatic.net/kXV5x.png)](https://i.sstatic.net/kXV5x.png)

Finally, here is a layer view of the print a few millimeters from the final top layer with the unrequested top/bottom layer that covers the spindle hole:

[![enter image description here](https://i.sstatic.net/Yd8mn.png)](https://i.sstatic.net/Yd8mn.png)

The STL file is on [Github](https://github.com/username_0-username_0/3dprints/blob/master/spindle.stl) (with a built-in viewer).

Can anyone help me understand why this is happening?

**Tags:** ultimaker-cura, slicing, troubleshooting

> **Comments:**
> **username_1**: Did you try to heal the stl in a program like MeshLab and slice the healed model?  
> **username_0**: No, I created a VTK file using Pygmsh and then converted it to STL using ParaView  

---

## 2 answers

### Answer by username_3 on 2019-08-22. Score: 4 | Accepted answer

It would appear that your model does not conform properly to STL standards. I base this conclusion on a couple of factors. When I loaded the model into Simplify3D slicer, it displayed fine, but when sliced, displayed nothing. Using the onboard repair feature, it presented the entire model as being composed of non-manifold surfaces.

Meshmixer's Analysis/Inspector feature also highlighted the entire model as flawed.

Another observation is that there is an extraordinary amount of facets/triangles/faces to this model. Nearly three-quarters of a million triangles for something that should be much simpler.

The most recent version of Prusa Slicer 2.0 presents an error message indicating that no layers were detected. This is peculiar indeed.

All of the above points to a problem with the source file or the software used to create it.

Please consider to add to your post the program you used or the source of the model.

> **Comments:**
> **username_0**: I created the mesh using Pygmsh which saved it as a VTK file. I then converted it to STL using ParaView. I can provide the source later this evening after work but it does seem that my STL file is indeed abnormal and that I should probably use a canonical CAD program.  
> **username_3**: From my brief bit of research, I see that Pygmsh is a facilitator for gmsh, which appears to be founded strongly in coding. To that end, consider to check out http://www.openscad.org for a scripting type 3d modeling program. Your cone might be three modules, maybe four at the most. Two cylinders (base and cone) and another cylinder subtracted from the union.  
> **username_0**: OpenSCAD is perfect, so much easier than my previous approach!  
> **username_3**: I'm happy to hear that you like it. It's my first attack program, unless the part/model is severely organic in shape.  

---

### Answer by username_2 on 2021-04-28. Score: 3

I had the same issue exporting from Sketchup to STL. I imported my STL to Tinkercad and then exported it again and it resolved my issue.

Tinkercad is a free and online tool.


---

