Aleph Objects has come out with a nifty fan kit to upgrade TAZ 3 and older printers, and comes standard on the TAZ 4. The original factory design of the duct only blows on the build. This is great for improving bridge capability, but fails to address one of the shortcomings of the Budaschnozzle design, which is the fact the it only has passive cooling above the hot end itself with fixed heat sinks. PLA in particular tends to get stuck in there due to heat creep up the 3mm filament. This addresses that problem by diverting some air onto those heat sinks. We have hundreds of hours of PLA builds with zero filament jams since installing this dual duct to our TAZ 3. Some people have had issues with the fan mount holes being a little too big to self-thread, so we reduced the diameter to 3.5mm and uploaded a new STL today on 6/23/15.Since this is designed to be 3D printed it needs no support. Since it is intended to be functional and doesn't need to be pretty, you can slice it fairly coarse, .25 or even .3mm layers should work fine. Make it with ABS or nylon so it can handle being near the hot end. I reduced the original screw holes for where the fan mounts so the screws can self-tap. The original holes were much larger to use threaded brass inserts.