My parts.

[eldonb]

The following are some AC3D parts that I had fun building, at first I thought they would be easy, but, I found them more challenging.

http://www.ebcon.com/AC3D/gallery/InterestingParts01.png

Here is the surface solution.

http://www.ebcon.com/AC3D/gallery/InterestingParts01s.png

I like to build AC3D parts for mechincal and electronic assemblies.

Eldon

[Spinner]

Could be an extra surface or two inside your round objects.
See that twinkle on the top bottom outer ring in the circle with square inside? That tends to indicate that.
You're on the right track with tasks like this. Master the program.

[SAT]

How did you make those without boolean operations?

[nightoftheroundtable]

you know that doesn't look to complicated. I could do the exact same thing with no boolean.