*stp import: make solid from wires

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justwanttoknow
Posts: 27
Joined: Fri Oct 08, 2021 9:21 pm

*stp import: make solid from wires

Post by justwanttoknow »

I am struggling a bit to import an *.stp into FreeCAD.
The aim is to use it within CfdOF, so it needs to be solid being able to get subtracted from a cube.

The step-file presented itself as just having definition lines (Normal for a *.stp?)
Screenshot from 2022-06-25 11-45-48.png
Screenshot from 2022-06-25 11-45-48.png (8.2 KiB) Viewed 650 times
First idea was to use draft-upgrade to work from wire to surface to solid, but the wires could not get upgraded.

Second idea was to make extrudes. Part-extrude worked basically with the following error message: "Part::Extrusion: Link(s) to object(s) 'Part__Feature001' go out of the allowed scope 'Extrude'. Instead, the linked object(s) reside within 'prodname'."

After trying various items a solid could be produced, but boolean cut ultimately fails with "Recompute failed! Please check report view."

Has anybody ideas on this? Yes, quickly rebuilding this simple wing would be easy, but it would be beneficial to exploit import potential.

Using step-files is still the way to go for import? Alternatives are .tri .igs .obj apart from .stl mesh and other mesh formats.

Thanks in advance!

Code: Select all

OS: Ubuntu 20.04.4 LTS (ubuntu:GNOME/ubuntu)
Word size of FreeCAD: 64-bit
Version: 0.20.28793 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 5386d4e)
Hash: 5386d4ed864cd03edd026e1d3d128cccedf568df
Python 3.9.12, Qt 5.12.9, Coin 4.0.0, OCC 7.5.3
Locale: English/United States (en_US)
Installed mods: 
  * CurvedShapes 1.0.3
  * CfdOF 1.17.0
  * Plot 2022.4.17
  * AirPlaneDesign 0.4.0
Attachments
naca4415stpimport2ndtry.FCStd
(264.25 KiB) Downloaded 5 times
naca4415ar12.stp
(282.85 KiB) Downloaded 11 times
naca4415stpimport.FCStd
(264.3 KiB) Downloaded 5 times
chrisb
Veteran
Posts: 53919
Joined: Tue Mar 17, 2015 9:14 am

Re: *stp import: make solid from wires

Post by chrisb »

What are the differences between the FreeCAD files? Which one should we look at?
Please help the helpers!
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
justwanttoknow
Posts: 27
Joined: Fri Oct 08, 2021 9:21 pm

Re: *stp import: make solid from wires

Post by justwanttoknow »

Sorry for confusing.

naca4415stpimport.FCStd was my first try, which resulted into a not usable solid.
naca4415stpimport2ndtry.FCStd was a fresh new approach to replicate. So this is a better basis for discussion.
Original *.stp-file also attached.
chrisb
Veteran
Posts: 53919
Joined: Tue Mar 17, 2015 9:14 am

Re: *stp import: make solid from wires

Post by chrisb »

I can open the step file. It shows errors on CheckGeometry. Part->explodeCompound and then a double Draft->Upgrade on the components creates a solid, which again shows errors. Despite the errors it is possible to create a boolean cut:
SnipScreenshot-b97176.png
SnipScreenshot-b97176.png (3.71 KiB) Viewed 619 times
Attachments
profile_cb.FCStd
(313.05 KiB) Downloaded 5 times
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
justwanttoknow
Posts: 27
Joined: Fri Oct 08, 2021 9:21 pm

Re: *stp import: make solid from wires

Post by justwanttoknow »

Thanks, Chris!

Trying to replicate from sketch I do not get the double draft-upgrade.

Choosing one compound=one side of the wing. Compound-explode.
Then COMPOUND.00-COMPOUND.71 are generated.
Marking those and draft-upgrade gives WIRE-WIRE06.
But marking those and second time upgrade does not give a solid.

Probably I've missed something....
Attachments
naca4415new.FCStd
(294.42 KiB) Downloaded 7 times
chrisb
Veteran
Posts: 53919
Joined: Tue Mar 17, 2015 9:14 am

Re: *stp import: make solid from wires

Post by chrisb »

these are my import options:
Bildschirmfoto 2022-06-26 um 21.58.53.png
Bildschirmfoto 2022-06-26 um 21.58.53.png (50.61 KiB) Viewed 481 times
Exploding one of the compounds yields 6 objects, not 72

I could also Downgrade and then upgrade the compounds.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
justwanttoknow
Posts: 27
Joined: Fri Oct 08, 2021 9:21 pm

Re: *stp import: make solid from wires

Post by justwanttoknow »

Fantastic! This has worked. Thanks, I would have never found these settings.
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