[Solved] 3D Offset tool problems

[skeptik]

Greetings everybody
I draw two hexagons. I connect them with edges, then I create faces and finally a shell. All using shapebuilder in Part Workbench. There's a bowl shape. Check geometry tool does not report any problem.

When I try to add a wall thickness with 3D Offset, I get an error message BRepFill_CompatibleWire:SameNumberByPolarMethods : the wires must be closed.

Please, advice me, what I'm doing wrong. Thank.

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16131 (Git)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 3129ae4296e40ed20e7b3d460b86e6969acbe1c3
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: Czech/CzechRepublic (cs_CZ)

[chrisb]

Hard to say without the FreeCAD file. Please upload.

[skeptik]

Thanks. Here it is.

[chrisb]

The only thing I can do is to confirm the issue even with a simplified version:

Snip macro screenshot-3b79bd.png (2.85 KiB) Viewed 1645 times

CheckGeometry says it is 1 Shell and when I try with a similar shell made from a single not closed sketch it works well:

Snip macro screenshot-17c0e7.png (2.61 KiB) Viewed 1645 times

[jaisejames]

First select all faces. then click menu Part -> join -> connect objects. Then apply offset. It will generate open 3d offset, not possible for filled shape.
Edit :
[reason for not a good filled shape, but i am not sure]
All faces normal should be pointing outward. but Some faces normal are towards inside. so some faces offset to inside.

[skeptik]

Thank you both.
The error message states "the wires must be closed".
Maybe you'll know which wires and how to close them...

[skeptik]

Additions:

When I use another procedure to create the same shape - using loft, everything works correctly.
However, the procedure used in the first case is more generally applicable and is the recommended workflow in the documentation.

[UR_]

Screenshot 002.png (14 KiB) Viewed 1614 times

Creation of top face is to difficult for PartWB:3D-Offset.

If you prefer building up from edges to faces to solid, top face has to build up same way.

3D-Offset is used to create outer shell (Fill Offset unchecked)
I used LatticeWB:Sublink to get access to vertexes and edges.

AAAA.FCStd

(219.55 KiB) Downloaded 13 times

[Vincent B]

Fill offset doesn't works. I made a forward offset, then a filled backward, it's works.

[skeptik]

Thank you all.
I appreciate your willingness and your time.