This fan duct is a perfect addition for your RF100 3d printer. Simply print it and attach it with some adhesive tape to the print head. It’s designed to fit snugly with a 50×50 PC fan. Due to the design you don’t loose any print area and get massive cooling because of the large fan.

Check it out on Thingiverse (+ Download)

Sweet, but why don’t you fix the fan with screws? And where do you connect the fan wires? Do you use separate power supply?

Answer: Thanks! 😀 The first attempt was to design a duct which can be screwed on, but then the casing of the extruder has to be removed which doesn’t look that good. Also drilling a hole in the housing was not a choice (warranty reasons). Then, I decided to use some double-sided tape which worked quite fine and can be easily removed.
The wires of the fan are bound to the tube (where the filament is brought to the extruder) using some zip-ties. I use an external power supply to control the speed of the fan with variable voltage or PWM-control, as it turned out that the heating element might be get too cool with full air flow, although I designed the duct to not blow at the heating element directly.