Printrbot Printrboard cooling fan bar mount

This thing allows you to mount a 70mm (OD) PC cooling fan to the back 2 bars of a Printrbot, thus blowing air across the Printrboard (specifically the stepper drivers). While I haven't heard any reports of Printrboards failing, I wanted to prolong the life of mine as long as possible. I run the fan directly off 5V from an ATX - it is a 12V fan so at this potential difference it runs slower and quieter providing a gentle airflow. At higher speed the cooling might be so great that it negatively af