I'm calling this a remix even though I redesigned this from scratch. I like the design but wanted to make some changes. I used "The Warthog" as a guideline for measurements, etc.
I found that the inner parts tend to sag a lot and this will disrupt the airflow. I also wanted a way to screw it on so it couldn't rattle loose while printing.
As you can see from the cutaway view (3rd pic), the inside has a triangle shape so it doesn't sag while printing (I verified this).
The screw mount uses the screws that are already on the fan mount. At first they don't seem to line up properly. But this is because it wants to go on crooked due to the shape of the insert. As you are looking at the side view (2nd pic) you push up on the right side and put the right most screw in. Then you can put the other screw in. This insures that it is mounted straight.
You shouldn't need any supports when printing this.
I was able to test fit everything, but I can't do any test prints yet. This printer was given to me and is missing a bunch of parts. I printed this on my Prusa. If anyone wants to try this and do some test prints, I would appreciate comments on how well it works (or doesn't work).
** Added v2 **
Ends are angled down more so hopefully it will not blow directly on the nozzle.