Extrusion of a self intersecting/open profile


Normally CATIA does not allow user to extrude an open or self intersecting profile. It is not possible to extrude such profile unless you define a thickness of the extrusion.
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https://catia-tnt.blogspot.com/2017/10/extrusion-of-self-intersectingopen.html
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Step 1:
Follow these steps to extrude an open and/or self intersecting sketch.
1. Create a sketch with an open and/or self intersecting profile - Fig.1.
Fig.1
2. Use this sketch to create a Pad, in the Feature Definition Error window click on Yes - Fig.2
Fig.2
3. In the Pad Definition, in Profile/Surface section check the option Thick - Fig.3. Click on More to expand the Pad Definition window.
Fig.3
4. Define thickness or thicknesses of the extrusion in the Thin Pad - Fig.4. And click on OK.
Fig.4
5. An extrusion of a self intersection and open profile has been created - Fig.5.
Fig.5