This is a remix of Josef's fan duct for the Mk2. I wanted something that better surrounded the nozzle to achieve finer detail on all sides of parts. It seems to have excellent air flow and it blows down on the part and not at the nozzle. It fits my machine perfectly hopefully it will fit yours as well. The file with "draft angle" is referring to the bottom of the duct facing the bed. I had been using a Micro Swiss nozzle, not an E3D nozzle and they are longer but I did not realize this when I initially designed it. This file was modified at the request of someone having clearance issues to the bed. Enjoy!
Added 3rd & 4th files. The 3rd file is a more complete circle around the nozzle and has tremendous airflow in all directions. The 4th file is a complete circle around the nozzle. It's airflow doesn't seem to be as good as the 3rd file but give it a go if you like.
Added second file with center flap.
Adjusted model with a slight draft angle to the bottom for better clearance.
I printed these in PLA for prototype use only with the intention of printing the final pieces in ABS but after using them in PLA I have had zero warping/melting on any of them. I even had a 35 hour print with no issues.