Need Help Drawing This Shape in 3D AutoCAD

[Bobzy20]

I’ve haven’t done any 3D CAD for about 3-4 months now and I can’t seem to remember how to draw this shape I found on the internet.

I'm trying to draw the section highlighted by the red circle.

Any help would be great.

[ReMark]

Wouldn't you create a curved "positive" of the fluted shape and subtract it from the oval tube you have above?

[Bobzy20]

Sorry might need more help.

[ReMark]

It looks like you are 90% of the way there judging by the image above. You are trying to derive the ridges (or flutes) in the oval portion of the ring are you not?

[Bobzy20]

I’m trying to somehow subtract the cylinder from the ridged ellipse shape so I will end up with something that looks like the diagram above. I manage to subtract the cylinder from the inside of the ellipse but that was easy as it doesn’t have a ridged face.

I can upload the CAD file if needed.

[ReMark]

Sorry, I got confused there. I did not have my first cup of coffee. Sure...post what you have. Someone here, not necessarily me, will figure it out.

[Bobzy20]

Here we go.

[Bobzy20]

Looks nice but the red part needs to go up and over at the top and bottom like the image above.

[ReMark]

Yeah, I realized that just after I took the dog for a walk. My bad.

For some strange reason I could not work with your geometry. I had to recreate the objects.

[Bobzy20]

Yeah I couldn’t either I had to re-sweep everything as I got an error saying: Inconsistent edge-face relationships.

Maybe it’s me or something to do with 2013.