OCC error when trying to thicken a wavy surface

[NewJoker]

Hi,

I am trying to apply a filled offset (Part Offset) to a wavy surface. Unfortunately, I am getting OCC errors regardless of the offset mode and join types:

offset error.JPG (75.45 KiB) Viewed 764 times

Any chances that it can be fixed ? Can you suggest some workaround ?

Wavy pizza cutter.FCStd

(27.49 KiB) Downloaded 20 times

Code: Select all

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.1.29410 (Git)
Build type: Release
Branch: releases/FreeCAD-0-20
Hash: f5d13554ecc7a456fb6e970568ae5c74ba727563
Python 3.8.10, Qt 5.15.2, Coin 4.0.1, Vtk 8.2.0, OCC 7.6.3
Locale: Polish/Poland (pl_PL)

[thomas-neemann]

....

is this a solution for you?

Bildschirmfoto_2022-10-02_20-22-22.png (52.35 KiB) Viewed 740 times

Wavy pizza cutter-tn2.FCStd

(53.94 KiB) Downloaded 20 times

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OS: Ubuntu 20.04.1 LTS (XFCE/xubuntu)
Word size of FreeCAD: 64-bit
Version: 0.21.30486 (Git) AppImage
Build type: Release
Branch: master
Hash: eb546e25d3f952869e3ec87dca02b58653cb3936
Python 3.10.6, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
Locale: German/Germany (de_DE)

[NewJoker]

is this a solution for you?

Yes, it looks good, thank you. I don't why I didn't think about Part Extrude. I was following a tutorial in which offset was used.

[user1234]

Just for completeness:

when you make a geometry check of the surface, you will see, that there are meany errors. The reason is because the array is not fused, so the seams of the array are open.

When it is fused, then the operation at least do something, but at least for me the result is invalid. But also my OCCT version is atm old (can not update because of an bug), on newer it could work better. If someone could test, this would be informative.

2022-10-02_20-47.png (230.99 KiB) Viewed 692 times

I don't why I didn't think about Part Extrude.

A extrude is not the same thing as an offset. An extrude only goes in one direction, a offset goes to the normal of the source surface (constant wall thickness). But because the wave is pretty "flat" at least it is a good near.


Greetings
user1234

[Vincent B]

or like this.

[chrisb]

If someone could test, this would be informative.

Doesn't really work here either. Only Joint type intersection yields a result:

SnipScreenshot-fad1c5.png (47 KiB) Viewed 567 times

Code: Select all

OS: macOS 10.16
Word size of FreeCAD: 64-bit
Version: 0.21.30430 (Git)
Build type: Release
Branch: master
Hash: 9e1ed4a68ad43309c2b38f7f5efbb1feac4323cb
Python 3.10.6, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
Locale: C/Default (C)
Installed mods: 
  * FC_SU
  * FeedsAndSpeeds 0.4.0
  * fcgear 1.0.0
  * fasteners 0.4.6
  * sheetmetal 0.2.57
  * ExplodedAssembly
  * Curves 0.5.8

[papyblaise]

or other solution

[Vincent B]

Doesn't really work here either. Only Joint type intersection yields a result:

Because mirror carry out up side downed surface. need part_ReversedShape. See my file.