Importing and Editing STL, "Shape is not a shell".

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-alex-
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Re: Importing and Editing STL, "Shape is not a shell".

Post by -alex- »

xanatos wrote: Wed Feb 08, 2023 3:51 pm This worked to allow me to create and print the part-pocket I needed, but I know there has to be a much more expedient way to do this rather than by brute force and manual pick & choose... Still hoping someone can load the stl and/or step I posted and let me know what the modified procedure would be... Thanks for any guidance.
Congratulation!
BTW I can't get your step file, error 404. Yesterday the same, so I was not able to have a look.
xanatos
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Re: Importing and Editing STL, "Shape is not a shell".

Post by xanatos »

-alex- wrote: Wed Feb 08, 2023 4:29 pm BTW I can't get your step file, error 404. Yesterday the same, so I was not able to have a look.
Apologies, the stl loads but not the step - apparently the server has something against step files :)

I've changed the file extension to txt. Use this link and change the file extension back to .step once you have it:

https://xanatos.com/downloads/4900%20QT ... 40step.txt

Thanks very much!

Dave
xanatos
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Re: Importing and Editing STL, "Shape is not a shell".

Post by xanatos »

Just wondering if anybody had any luck in opening the step file. I'm still having issues... Thanks
drmacro
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Re: Importing and Editing STL, "Shape is not a shell".

Post by drmacro »

Step file from the last link you provided seems ok. I checked a few components and they pass geometry check.
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xanatos
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Re: Importing and Editing STL, "Shape is not a shell".

Post by xanatos »

drmacro wrote: Thu Feb 09, 2023 10:56 pm Step file from the last link you provided seems ok. I checked a few components and they pass geometry check.
Do you see any reason that I couldn't turn it into a solid so I can do Boolean operations on other objects with it? It refuses to convert to a solid :)
drmacro
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Re: Importing and Editing STL, "Shape is not a shell".

Post by drmacro »

xanatos wrote: Thu Feb 09, 2023 11:05 pm
drmacro wrote: Thu Feb 09, 2023 10:56 pm Step file from the last link you provided seems ok. I checked a few components and they pass geometry check.
Do you see any reason that I couldn't turn it into a solid so I can do Boolean operations on other objects with it? It refuses to convert to a solid :)
An imported step file is a solid. There are just a whole bunch of solids.

You can see here I cut a channel through the board.
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xanatos
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Re: Importing and Editing STL, "Shape is not a shell".

Post by xanatos »

OK, then maybe I'm approaching things wrong. If I create a cube, move the item in the step file onto the cube and into it slightly, and with the cube, I attempt to cut the step file item out of the cube (effectively wanting to create a "mold" image of the item on the cube) - it won't let me.

If I select the imported step object and select it and try to perform a "union" on it, it says "Illegal storage access! Please save your work under a new file name and restart the application"

If I import the step file, and (from the Part workbench) I "Create shape from Mesh", it does that OK (the step object now has hundreds of little lines all over it... but that appears to be correct)

If I then select the newly created shape, and attempt to "Convert to solid", I get the error "Shape is not a shell".

I need to be able to do - whatever it is - so I can use these board stls or steps to be able to cut out their shapes from other simple objects like cubes, etc.

I don't need to do much to the boards themselves (the items in the step files) - I just need to use those to cut their impressions out of other objects.

Thanks for any help
drmacro
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Re: Importing and Editing STL, "Shape is not a shell".

Post by drmacro »

This step file contains many solids. If you use Part Check geometry on any single solid it is good. But, if you Check geo on the Std_Part container (the yellow icon) that contains them all, there are a mess of overlapping faces and edges. Also, a lot of bad curves. The overlaps are probably where the various components touch the pads on the board. This means the conversion to mesh is not going to produce a valid mesh that can be converted to a shape and then to a solid.

Somebody else may have some ideas. I'll have a look in the morning to see if I can get something usable using Blender to do a shrink wrap around it.

(The usual tricks like loading it into VariCAD and saving didn't work for me...)
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
xanatos
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Re: Importing and Editing STL, "Shape is not a shell".

Post by xanatos »

That explains much, thank you. Shrink-wrapping sounds like a hopeful idea. I'll look into Blender in the morning, in case it turns out that works. Is that a separate package or part of FreeCAD?
drmacro
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Re: Importing and Editing STL, "Shape is not a shell".

Post by drmacro »

xanatos wrote: Fri Feb 10, 2023 1:17 am That explains much, thank you. Shrink-wrapping sounds like a hopeful idea. I'll look into Blender in the morning, in case it turns out that works. Is that a separate package or part of FreeCAD?
See: https://www.blender.org/
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
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