Printrbot compatible extruder fan duct and mount. This fan duct primarily cools the hot extruded thread. This ducting provides some additional cooling for the extruder collar/mount as well. Design DOE's and optimizations by me. The wonderful CAD work on these were provided by my friend Eric D., as he is so much faster at CAD work than I am.
I have three variations of Extruders for my project that I used for fit during this design. The duct mount is meant to fit between your x-carriage mount and your extruder drive. You can attach the fan ducting on the top or bottom of the mount tabs to fit your exact dimensions. The primary cooling output is meant to cool the hot extruded output and not the nozzle. Assure that the ducting does not extend below the extruder nozzle. The secondary cooling output (to the extruder collar/mount)is optimally spaced to be within a half of an inch (~13mm).
Support ribs were specifically incorporated into the design to allow non-cooled printing of these parts, control flow, and to provide additional strength to the ducting.