This is a modification of https://www.youmagine.com/designs/ultimaker-fanduct-v2 and https://www.youmagine.com/designs/umo-fanduct-for-3dsolex-and-e3d-nozzles to use 40mm fans and attempted to create a right side version with the extended mount to get clear of the nozzle.
The orginal design are for 50mm fans, as I had a couple of good 40mm fans, I modified the design to mount 40mm fans.
Still not printed so I dont know if its a 100% fit.
Will print in Colorfabb XT as soon as I get time.
Technical
2x 40mm fans, I'm using Noctua (http://noctua.at/en/nf-a4x10-flx)
4 x 18mm M3 screw per fan
4 x M3 nut (preferable nylock nut) per fan
You stick the screws in from the underside and the nut ontop of the fan
Just in this this helps:
https://ultimaker.com/en/community/20524-ultimaker-original-dual-fan-upgrade-contributed-by-neotko
It's design it's planned for e3d/3dsolex nozzles on umo+. The youmagine files have also step/rhino files so you could make your own quite fast.
Cheers!