Flashforge extruder cooling duct

remixed from http://www.thingiverse.com/thing:327387 all that was done was some parts were made longer to fit my specs. I did have to shave a little off the tray to make it sit nice and flush to everything

EDIT: To clarify: When I fitted this part to my extruder, I did have to cut two or three layers off of the tray that fits under the fan so that the shroud could contact the fan. It may be that trezhunter's part would have fit as-is if I had tried that, ymmv