> I don't understand why I can't seem to generate the back wall
> center, even though it was selected with the other bits that
> have spinned into surfaces.

I'm not following this part, you may need to post the actual model file to clarify this question.


But if I understand your drawing correctly, I think you want to draw the entire outline with all sharp edges at corners, then use the extrude tool to extrude it out, and then fillet everything after that.

The key thing thing here is that if you extrude a shape that has other curves nested inside of it, those nested curves will be void areas inside the extruded solid. The other strategy thing is that if you're going to make a lot of little rounded edges it can be a lot easier to keep everything sharp and do all the rounds at once, rather than trying to build different sections at a time.

Drawing the curves involved quite a lot of different little steps. I've attached the model that shows things in various stages, I started by drawing an octogon, rotated it, drew several circles and then a bunch of lines for the little spokes, mirrored and rotate/copied some lines around and then trimmed the circles and spokes with each other to form the solid regions. Let me know if you want some more details on any of these steps, there is a lot of little fiddly parts to this.

Then I did an extrude to punch the shape up and leave holes for those inside regions. Then I selected the outside edges and filleted them with a larger radius, then I selected everything and did another fillet, you'll have to wait for a minute as it tries to do the same larger radius which produces a strange result on the little pieces, stay in fillet and enter a smaller radius, like 0.05, that was more appropriate for the size of the little spoke pieces. You would probably want to make the spokes a little larger if you wanted to do a larger radius.

Was this the type of result you were looking for? Let me know if you want any more info on any particular stage.

There may be some sloppy parts in this one, I did it kind of rushed. It's kind of a heavy model because of so many little roundy bits.

- Michael