Can't create solid because shape is not a shell

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maxcwy2017
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Joined: Mon Nov 02, 2020 2:30 pm

Can't create solid because shape is not a shell

Post by maxcwy2017 »

I need to do fuel injector simulation with AVL FIRE but instead I found out my body of my model is hollow instead of a solid, so I tried to search on the internet and I found out that I can turn it into a solid with FreeCAD but when I was trying to turn it into a solid, I got an error saying the shape is not a shell and I searched on the internet that what is the error about and I tried evaluate and repair mesh and it found no whatsoever error. So now I am confused that why couldn't my model be turn into a solid. Is there any way to fix this problem ? I had attached the file within this post. As I am new to doing these kind of stuffs so I am all ears to receive any guidance. Thank you for your help.
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Injector.obj
(237.63 KiB) Downloaded 74 times
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papyblaise
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Re: Can't create solid because shape is not a shell

Post by papyblaise »

Fc quickly gets into error as soon as the object is a little complex, I think this is the case here
maxcwy2017
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Re: Can't create solid because shape is not a shell

Post by maxcwy2017 »

papyblaise wrote: Thu Nov 19, 2020 12:43 pm Fc quickly gets into error as soon as the object is a little complex, I think this is the case here
Is there any software that I can use besides from FreeCAD to make a hollow body to a solid?
chrisb
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Re: Can't create solid because shape is not a shell

Post by chrisb »

Instead of investing time to convert it - which will still leave it deteriorated with its tesselation - You can remodel it from scratch: A revolve of a sketch containing probably less than 10 lines for the body. Then one sketch for each layer of sticks, pad, and a polar pattern.
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drmacro
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Re: Can't create solid because shape is not a shell

Post by drmacro »

Looks like there are a few non-manifold areas in the mesh (in Blender)

Need to fix that somehow.
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maxcwy2017
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Re: Can't create solid because shape is not a shell

Post by maxcwy2017 »

Any guide or tutorial of doing that? Because I am kind of being pressured by the person in charge to do a simulation on AVL FIRE ASAP and so I hope to finish it quickly.
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Willem
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Re: Can't create solid because shape is not a shell

Post by Willem »

Here a video about how to use the mesh ( OBJ file ) for creating a Freecad solid model
phpBB [video]
chrisb
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Re: Can't create solid because shape is not a shell

Post by chrisb »

Willem wrote: Thu Nov 19, 2020 3:00 pm Here a video about how to use the mesh ( OBJ file ) for creating a Freecad solid model
That's the way to go.
I hadn't seen this post, and have modeled it too. I attach my solution as well, because I solved the issue with the tangent differently and it is made in PartDesign, in case the tubes at the tip should be part of the solid. Then adding further things could be easier in PartDesign.

In the mesh these cylinders are not connected, is this on purpose?
Snip macro screenshot-b16d81.png
Snip macro screenshot-b16d81.png (7.66 KiB) Viewed 9305 times
An additional note: Willem, you stopped the polyline when it came to the arc. Please try the M-key for different continuation modes.

I have removed the mesh, it would ave inflated the model from 37KB to nearly 800KB.
Attachments
injector_cb.FCStd
(36.38 KiB) Downloaded 42 times
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maxcwy2017
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Re: Can't create solid because shape is not a shell

Post by maxcwy2017 »

chrisb wrote: Thu Nov 19, 2020 9:29 pm
Willem wrote: Thu Nov 19, 2020 3:00 pm Here a video about how to use the mesh ( OBJ file ) for creating a Freecad solid model
That's the way to go.
I hadn't seen this post, and have modeled it too. I attach my solution as well, because I solved the issue with the tangent differently and it is made in PartDesign, in case the tubes at the tip should be part of the solid. Then adding further things could be easier in PartDesign.

In the mesh these cylinders are not connected, is this on purpose?
Snip macro screenshot-b16d81.png

An additional note: Willem, you stopped the polyline when it came to the arc. Please try the M-key for different continuation modes.

I have removed the mesh, it would ave inflated the model from 37KB to nearly 800KB.
The cylinders are connected if according to CREO 4.0 because I was doing the model using that software and then import into FreeCAD.
chrisb
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Re: Can't create solid because shape is not a shell

Post by chrisb »

maxcwy2017 wrote: Fri Nov 20, 2020 7:09 am The cylinders are connected if according to CREO 4.0 because I was doing the model using that software and then import into FreeCAD.
Creo can most probably export to STEP, so you should use that format. STL or OBJ is really a bad format for transporting CAD models, because it is lossy. You can see this very well with the different solutions proposed here for the tip of the injector. And finally they may both be wrong.
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