40mm Fan Mount for Cooling Printrbot Simple Filament Entrance

I was having issues with my PLA melting early and buckling inside of the extruder during long prints. After looking at many other solutions for inspiration, this is what I came up with. It seems to work quite well, although I'm considering opening up the top of the extruder a little bit for additional airflow.

I replaced the four extruder motor screws with M3x40mm screws. I also used a 12VDC 40mm fan from Radio Shack and 6x3/4 sheet metal screws to attach the fan to the mount. This mount does not interfere with the two screws that hold the extruder in place.

As an additional note, it appears that there is too much backpressure with a 12V 40mm fan. It doesn't seem to be a problem with PLA, but I'm finding it makes things too cool for ABS and I'm getting some warping that I wasn't before. I recommend adding a switch or potentiometer to the fan power in order to regulate fan speed or turn it off entirely for ABS prints.