STL to Solid - "Part object is not a shell" error

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wmayer
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Re: STL to Solid - "Part object is not a shell" error

Postby wmayer » Tue May 20, 2014 9:39 am

The basic problem is that your mesh consists of five independent solids which are not correctly put together. This usually happens with tools like Blender or similar 3D-graphic software which has the focus more on nice-looking than on correctness.

Anyway, it's fairly enough to convert your mesh into valid Part solids. The trick is to separate the individual components into own meshes. Currently there is no GUI command that does this automatically. So, what you can do is to copy/paste the original mesh four times to have five versions. Then use the command from "Remove components by hand" and go through the meshes and isolate the corresponding components (i.e. always remove the other four components).

After this is done you can convert all meshes into own Part objects and later convert them to solids. As final step you can do a boolean fusion of the five solids.
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shoogen
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Re: STL to Solid - "Part object is not a shell" error

Postby shoogen » Tue May 20, 2014 9:55 am

wmayer wrote:3D-graphic software which has the focus more on nice-looking than on correctness.
The meshes don't need to be manifold, watertight or non-self-intersecting for their purpose. And i think correctness might depend on the point of view. The FreeCAD Mesh module reports a lot of "folds on surface" for this model. Would anybody might explain to me what this means? Because a loft oft meshes that i use, and a reported to be fine by other tools, have these problems and i would like to know the implications.
arhabib
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Re: STL to Solid - "Part object is not a shell" error

Postby arhabib » Mon May 26, 2014 2:30 am

Hey Guys;
I tried this part-by-part conversion to a solid, but was unsuccessful.
Can someone convert this mesh to a 3D solid and send it to me, please?
This will be really appreciated.
Thanks
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quick61
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Re: STL to Solid - "Part object is not a shell" error

Postby quick61 » Mon May 26, 2014 3:11 am

arhabib wrote:Hey Guys;
I tried this part-by-part conversion to a solid, but was unsuccessful.
Can someone convert this mesh to a 3D solid and send it to me, please?
This will be really appreciated.
Thanks
I don't know which version you have but it was a rather simple process to convert the 5 separate pieces into solids and fuse them. Here is a link to the file with all the history intact. The Part Fusion is the end result. Sense we are coming back from a mesh, it's not going to refine any more than what it is. Here is the link to download. - https://www.dropbox.com/s/yegtzgmduevq7 ... idus.fcstd (4.87 MB)

cryptocleidus010, 011, 012, 013, and 014 are Part Refine which were then converted to solid and used in the fusion.

Mark

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arhabib
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Re: STL to Solid - "Part object is not a shell" error

Postby arhabib » Tue May 27, 2014 2:23 am

Hey Mark;

Thank you so much for doing this.
I was really stuck!

I am using FreeCAD 0.13 on Windows, I don't know if this can be an issue though.

Thanks again.
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quick61
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Re: STL to Solid - "Part object is not a shell" error

Postby quick61 » Tue May 27, 2014 2:41 am

arhabib wrote:Hey Mark;

Thank you so much for doing this.
I was really stuck!

I am using FreeCAD 0.13 on Windows, I don't know if this can be an issue though.

Thanks again.
Sure thing, and I would recommend that you upgrade your FreeCAD to version 0.14 ASAP. The "official" 0.14 will be coming along any day now and if your doing any important work between now and then, it sure won't hurt to use one of the more recent 0.14 builds for windows. If you get one that is a zip file all you need do is download, extrace and run FreeCAD.exe from the /bin folder. No installing needed and you can still keep the old 0.13 version. If you need textString support, this version is the one you want - viewtopic.php?f=4&t=6091 If not, either of the first two or so from here will do, depending if you are running 32 or 64 bit OS - http://sourceforge.net/projects/free-ca ... 0unstable/

Mark
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Scratchbuild
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Re: STL to Solid - "Part object is not a shell" error

Postby Scratchbuild » Tue Mar 14, 2017 4:09 am

Hi there,

I know this is an old post but just to help people that still has this problem.

What I do is first repairing the STL with netfabb online service. They make sure the stl is a shell in there insperction and repairing. You can then import the stl into freecad and follow the procedure above. It works most of the time but there is times that even netfabb fails.

Regards

The Xanics.com 3D team
3D printing fun
chrisb
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Re: STL to Solid - "Part object is not a shell" error

Postby chrisb » Tue Mar 14, 2017 7:27 am

Thanks for the hint.
quick61 wrote:Sure thing, and I would recommend that you upgrade your FreeCAD to version 0.14 ASAP.
It was funny reading Mark's comment urging to upgrade. While I don't really miss the good old 0.13 from the times where we still had an emperor and everything was made from wood I do miss Mark's comments. He helped me a lot with my first FreeCAD steps.
genesis678
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Re: STL to Solid - "Part object is not a shell" error

Postby genesis678 » Thu Mar 16, 2017 10:19 am

Scratchbuild wrote:Hi there,

I know this is an old post but just to help people that still has this problem.

What I do is first repairing the STL with netfabb online service. They make sure the stl is a shell in there insperction and repairing. You can then import the stl into freecad and follow the procedure above. It works most of the time but there is times that even netfabb fails.

Regards

The Xanics.com 3D team
3D printing fun
Thanks for the post. I just ran into this issue and tried your solution. I was a litle hesitant since I had to verify through my gmail but just created a new email and it worked fine. Good thing too since you just posted the other day and this thread is old. Thanks!
Maryfreecad
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Re: STL to Solid - "Part object is not a shell" error

Postby Maryfreecad » Mon Aug 13, 2018 2:33 pm

NormandC wrote:
Mon May 19, 2014 3:31 am
Hello,
I have the same problem. Is there anybody to help please?

To convert a mesh object to a solid, here are the steps:
  1. Switch to the Part workbench
  2. Select the mesh, and go to the Part menu --> Create shape from mesh
  3. Click OK to the dialog
  4. Select the newly created shape
  5. Go to Part --> Convert to solid
  6. Select the newly created solid
  7. Go to Part --> Refine shape
The last step is not necessary, but it will clean the solid of most of its residual edges on planar and cylindrical surfaces.