<p>While without the files it's a guessing game, we can make an educated guess: the most frequent and likely culprit for this sort of faults is the model not being a manifold.</p>
<p>Most likely you've created several objects in Blender, and visually they comprise the shape you want, but internally they intersect, creating a lot of unnecessary internal geometry under the surface, and Cura fails to deduce what parts of the geometry are the actual &quot;skin&quot; of the object.</p>
<p>First, if your shape is composed of multiple objects, use the Boolean Union modifier, to merge them into a single object. Besides that, install &quot;3D Printing Toolbox&quot; add-on in Blender, find it in the sidebar tabs, and use the &quot;Make Manifold&quot; option, and inspect your shape to make sure it worked correctly and removed everything &quot;under the surface&quot;, leaving only hollow skin. If it failed, you may have to do that manually.</p>

CC BY-SA 4.0
2024-01-26T10:00:37.437Z
however, the model did slice for *one* profile, but not another
Trish
CC BY-SA 4.0
2024-01-26T10:05:58.113Z
@Trish Cura can deal with *some* of non-manifold shapes, sometimes correctly deriving the manifold shape, sometimes rather poorly, creating extra walls embedded in infill, and sometimes not at all, either failing to solve the shape or creating something seriously wrong, e.g. creating hollows in the volume where two solids overlap, making them connect with a single thread of filament.  Or even just crashing. The only way to get the results *reliably* is to resolve it at the modelling stage.
SF.
CC BY-SA 4.0
2024-01-26T10:28:09.083Z
Yes, but OP seems to describe to have a reliable outcome for *one* printer but never for *another*
Trish
CC BY-SA 4.0
2024-01-26T10:28:22.210Z
Yeah, I was able to fix. Thanks. I wasn't aware of those caveats!
Mark
CC BY-SA 4.0
2024-01-26T10:29:19.897Z
@Trish correct, but using those hints now Cura slices also for the Dremel. My wild guess is the path generation takes care of specific features of each printer
Mark
CC BY-SA 4.0
2024-01-26T10:32:33.900Z
self repair of Cura is a guesswork usually, but if fixing the model helped, good enough!
Trish
CC BY-SA 4.0
2024-01-26T09:52:45.220Z
2024-01-26T09:52:45.220Z
SF.
<p>I drew this object by myself using Blender:</p>
<p><a href="https://i.sstatic.net/xHma4.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/xHma4.png" alt="enter image description here" /></a></p>
<p>Importing the STL in Cura v5.3.1 under Ubuntu 23.10 I'm able to slice it for a Sovol SV04 printer, but if I select the Dremel 3D45 printer it fails:</p>
<p><a href="https://i.sstatic.net/k5Wo3.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/k5Wo3.png" alt="enter image description here" /></a></p>
<p>I don't see any &quot;red&quot; spot on the model that would tell me it's damaged.</p>
<p>What could prevent the slicing changing the model of the printer?
How to understand why it cannot slice and how to fix then?</p>

CC BY-SA 4.0
2024-01-24T14:44:22.903Z
We can't say without knowing a) your cura version and b) having access to the model
Trish
CC BY-SA 4.0
2024-01-24T14:52:44.967Z
@Trish question updated with the Cura version. About the file I've asked [here](https://3dprinting.meta.stackexchange.com/questions/591/how-to-share-an-stl-file) before opening this question. However, how should I share the file?
Mark
CC BY-SA 4.0
2024-01-24T15:50:18.570Z
Good question. I believe this might be a bug or a setting in your dremel profile that is incompatible. This might be better reported as a bug than asked here.
Trish
CC BY-SA 4.0
2024-01-26T07:35:20.860Z
Did you check the Cura log file? It might provide information as to what exactly fails.
Bob Ortiz
CC BY-SA 4.0
2024-01-26T10:28:55.057Z
Just to clarify: can you *repeatedly* slice this model for Printer A but never for Printer B?
Trish
CC BY-SA 4.0
2024-01-26T10:30:14.013Z
@Trish, exactly
Mark
<ultimaker-cura><slicing><dremel-3d45>
Why Cura cannot slice this object?
Mark
# Why Cura cannot slice this object?

(Asked by: username_0 on 2024-01-24)

I drew this object by myself using Blender:

[![enter image description here](https://i.sstatic.net/xHma4.png)](https://i.sstatic.net/xHma4.png)

Importing the STL in Cura v5.3.1 under Ubuntu 23.10 I'm able to slice it for a Sovol SV04 printer, but if I select the Dremel 3D45 printer it fails:

[![enter image description here](https://i.sstatic.net/k5Wo3.png)](https://i.sstatic.net/k5Wo3.png)

I don't see any "red" spot on the model that would tell me it's damaged.

What could prevent the slicing changing the model of the printer?
How to understand why it cannot slice and how to fix then?

**Tags:** ultimaker-cura, slicing, dremel-3d45

> **Comments:**
> **username_1**: We can't say without knowing a) your cura version and b) having access to the model  
> **username_0**: @username_1 question updated with the Cura version. About the file I've asked [here](https://3dprinting.meta.stackexchange.com/questions/591/how-to-share-an-stl-file) before opening this question. However, how should I share the file?  
> **username_1**: Good question. I believe this might be a bug or a setting in your dremel profile that is incompatible. This might be better reported as a bug than asked here.  
> **username_2**: Did you check the Cura log file? It might provide information as to what exactly fails.  
> **username_1**: Just to clarify: can you *repeatedly* slice this model for Printer A but never for Printer B?  
> **username_0**: @username_1, exactly  

---

## 1 answers

### Answer by username_3 on 2024-01-26. Score: 3 | Accepted answer

While without the files it's a guessing game, we can make an educated guess: the most frequent and likely culprit for this sort of faults is the model not being a manifold.

Most likely you've created several objects in Blender, and visually they comprise the shape you want, but internally they intersect, creating a lot of unnecessary internal geometry under the surface, and Cura fails to deduce what parts of the geometry are the actual "skin" of the object.

First, if your shape is composed of multiple objects, use the Boolean Union modifier, to merge them into a single object. Besides that, install "3D Printing Toolbox" add-on in Blender, find it in the sidebar tabs, and use the "Make Manifold" option, and inspect your shape to make sure it worked correctly and removed everything "under the surface", leaving only hollow skin. If it failed, you may have to do that manually.

> **Comments:**
> **username_1**: however, the model did slice for *one* profile, but not another  
> **username_3**: @username_1 Cura can deal with *some* of non-manifold shapes, sometimes correctly deriving the manifold shape, sometimes rather poorly, creating extra walls embedded in infill, and sometimes not at all, either failing to solve the shape or creating something seriously wrong, e.g. creating hollows in the volume where two solids overlap, making them connect with a single thread of filament.  Or even just crashing. The only way to get the results *reliably* is to resolve it at the modelling stage.  
> **username_1**: Yes, but OP seems to describe to have a reliable outcome for *one* printer but never for *another*  
> **username_0**: Yeah, I was able to fix. Thanks. I wasn't aware of those caveats!  
> **username_0**: @username_1 correct, but using those hints now Cura slices also for the Dremel. My wild guess is the path generation takes care of specific features of each printer  
> **username_1**: self repair of Cura is a guesswork usually, but if fixing the model helped, good enough!  

---

