A remix of Maurits' fan duct, designed for Rostock style printers to attach a 40mm fan. It is designed to work with Jason's LED ring (http://www.thingiverse.com/thing:32472) and is set for the proportions of Steve's hot-end for the Rostock Max.
Version 2 is much easier to print, gives you a choice of two different mounting plates and allows for fast removal of the duct for maintenance of the nozzle.
Edit 12.03.2013: Both versions are designed for the first gen nozzle! They don't necessarily work with "THE NEW" nozzle!
Print it aligned flat on the fan mounting flange. Prints well in PLA and does not melt if properly adjusted (I used a lighter to slightly heat the mounting bracket to fine adjust the position in height).
It should print without raft or support. Maybe you need to tape or weigh the fan mounting flange down mid print, to prevent the part from seperating from the build plate.
Use the mounting plate which fits to your build. The duct is meant to be mounted on one of the deep corners of the hot-end platform. Use a 1mm metal pin to attach the duct to the mounting plate (e.g. from a paper clip).