Hi rich, by default when you do a Revolve it will put end caps on planar openings to make the revolve a solid. That's what has happened here so your top revolve is a solid with no unjoined edges. Meanwhile the Join command only joins things together where unjoined edges touch each other.
So you'd need to either delete the bottom end cap or uncheck the "Cap ends" option in the Revolve command to get the unjoined bottom edge that could then be joined to another object.
- Michael
|
