This is a remix of the Smartfriendz hot end cooler from the smartrapcore alu printer. It is designed for the e3d v5 hot end, will fit on other printers also especially deltas, It incorporates a part cooling duct for PLA, the second object is a cover for the duct if you want to switch to printing ABS.
This keeps mass low on your corexy or delta print head and allows part cooling without the added complexity of additional fans.
Made a slight modification to internal profile of the duct to get more air through.
(I have tightened the leaky nozzle in the photo now)
There is now a version 2 http://www.thingiverse.com/thing:1360007 with a slide shutter to open/close (part close) the cooling duct, making it easier to switch between ABS and PLA, needs fairly high resolution to print well.
Kossel Mini/SmartRapCore Alu
Print the fan shroud keeping the orientation I've used here, this aligns the layers perpendicular to the hot end heatsink, to prevent cracking when it is squeezed over it. It can be printed rotated 90 deg but the layers are then parallel to the heatsink and can debond when attaching the part to the printer. Supports are helpful.
I filed the external sides of the duct opening with a fine flat file to get the duct cover to fit snugly.
I am planning on making an extension to the duct for more directed airflow.