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.

ridged ellipse.zip

[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.

[Bobzy20]

Another attempt gone wrong!

[ReMark]

As I drink more coffee I seem to be getting closer to a solution. I think.

[Bobzy20]

Looking better we just need to sort out the top and bottom part so it has smooth contours and bends in with the rest of the model where they meets.

[ReMark]

We? Who's this "we" you mention?:lol:

 

Yes, my "solution" is not exactly elegant by any means. It definitely needs some refinement. Actually, I don't like the way I did it and I keep thinking back to my first suggestion regarding subtracting a "positive" profile of the object. I just haven't figured it out yet.

[Bobzy20]

I always say ‘we’ so it sounds like we are in it together although you seem to be doing all the work which I appreciate.

 

Well if you or anybody else out there manages to find a solution it would be great to see.

 

We can crack this together!!!

[ReMark]

WE certainly can!

 

I'll give it another try after I finish this isometric I'm working on. Of course there's always a good chance JDM will come along and solve it using Inventor then we'll have to hear the "speech" again.

[JD Mather]

Trim extruded elliptical surface to the "belt-buckle" shape.

Thicken.

Sweep cut the "ribs".

Add fillets.

[ReMark]

And don't forget, "This would be so much easier if you bought a modern MCAD program like Inventor.":lol:

[JD Mather]

And don't forget, "This would be so much easier if you bought a modern MCAD program like Inventor.":lol:

 

or use FREE Inventor Fusion http://labs.autodesk.com

[Dadgad]

I am curious how this grew a second of the difficult parts.

In the original picture you got from the internet, there is only one of them?