this uses a slight remix of rsilvers filament drive and a little inspiration from neousagi. i have added some dovetails to the sides if the filament drive then designed an easily removable hot end cover that slips on to the filament drive. with the stock 30mm fan duct its difficult to remove the e3d hot end because you have to slide the duct off the top or bottom of the cooling fins. now you can just slide the cover off and remove the hotend. very easy just like the way the stock makergear hotend is to service. i have now updated the files to include versions for the v5 and v6 hot end. i have also designed an easily removable bed fan duct which uses a 40mm fan. this is a quick 2sec on off so you dont have to keep your bed fan on the machine unless you need it. the hinge pin on the duct just catches in the groove on the the 30mm cover then it just rotates down and snaps in place with a couple detents.
NOTE: a couple people have mentioned the parts fit a little tight. please read the instructions.
update 3/11/15 : i removed the old bed cooling duct and uploaded a 2nd revision. this duct is moved out about 1/8" so that it is centered on the heater block. this also allows slightly more room for the extruder wiring.
this is modeled in rhino5. once you print this use some 220 grit sandpaper to smooth out the layer marks from all the edges and face of the dovetails on the drive and duct. once you do that the duct should slide on and off like butter. both files print very easy with support but be sure to remove support on the duct from inside the dovetail area since it can be hard to remove from the tiny corners.
the fit on the dovetails is made a little tight. you are supposed to sand the layer marks out so the male and female part of the dovetails are nice and smooth. even if its modeled to be loose i found a sliding action is tough because of the layers grabbing. they make like teeth. if i make it any looser then by the time you sand everything smooth it will be too loose. a little 220 grit sand paper on all the sliding parts to smooth them out makes a world of difference. mine slides on and off easily with just 2 fingers and has a nice machined fit and feel to the sliding operation. print all the parts 90-100% solid.