I made a few modifications on the design, making it a tighter fit on both the printer and the cooling fan. No more need of tape, it sticks very firmly together.
This also means that it's more difficult to install: you'll want to use a softer material like PETG or ABS, that bends a little when putting in place.
I also improved the airflow, there is more air coming through the vent now.
It's intended to be used with a 24V 50x50x15 mm blower fan. Check out the original thing for details on how to wire the fan to the circuit.
The fan adds a half inch width on the back, which might collide with the bed support when starting from home position (with bed all the way up) and moving all the way to the left. I recommend printing a shim for the Y axis.
- Updated on 1/31/2016 to direct the airstream a little lower, directing the airflow away from the extruder.