i had the need for some more effective cooling today and as my custom carriage is still some time away i quickly did a new fanduct that offers some more concentrated air flow. It might not fit your needs but it does work quite good for me so i thought i’d share it.
See some render pictures attached - the duct is just the yellow part obviously
The stl file is here: http://hel.me/eusthatios_duct and here’s he Step-File which should hopefully work in your favourite 3D CAD: http://hel.me/Euthatios_Duct_step - let me know if you need anything else.
Regarding the print I did mine in Colorfabb XT CF 20 (PETG with Carbon fibre) and printed it upright without support (there’s just one small bridge that is a bit of a challenge, everything else is quite easy to print.
The hole on the left works with the screwhole in the default carriage but works the other way around i just attached it with a slightly smaller screw, therefore the hole in the duct is only 2mm.