Background

I have an older home and the bathroom vent fan uses a smaller diameter than they sell now. Not wanting to have to try to inline some kind of reducer in-line, I just designed one to fit.

Parts

Assembly

You need a ring clamp and ladder and it is still a PITA to get installed. Probably also some caulk.

Things I Learned

Give your parts some gaps between them if they have to connect in the real world.
A lot of small holes can slow down rendering of a part if you're designing on an iPad. Best to do that last.

The rendering of the vent