Hey again,

I think I’ve solved the first problems now! Turns out my inner profile curve had fewer points than the outer one. So instead, I offset the inner curve to create the outer — that way they matched. After that, I could run the Sweep operation, and I got caps on both ends. From there, it was easy to create the inner and outer solid surfaces, and then I used a Boolean to cut out the inner solid. So I guess the initial problem was the mismatch between the profile curves.

Now I’ve run into some new issues while adding fillets. See my screenshots!

1. I added a few more details to the model.
2. When I selected all the inner edges and applied a fillet, it seemed to work — but when I looked closer, the fillet corners don’t align properly.
3. I also noticed that the fillet on the outer top edge doesn’t match up with the side surface.

Could someone please take a look at my 3DM file again and help me figure out why this is happening? The file includes some layers (styles) showing the model in different stages.

Thanks again — really appreciate the help!