Printrbot Simple Metal extruder fan mount and switch housing
I was finding that long prints were failing on my Printrbot SImple Metal. The extruder motor seemed to be really warm so I installed a fan as some of the forums suggested. Here is my solution to a mount. I also installed a switch to turn the fan on and off when I was not using it.
rocker switch: http://www.amazon.com/dp/B00KD64MAK/ref=twister_B00KD64MBE