After a number of failed marathon prints (2+ hours) I realized I had an issue with the feed system getting too hot. So I created this thing to hold a 50mm fan in front of the assembly. The hole for the fan is sized to use a case fan screw and the hole on the printrbot side is sized for an M3 screw (already on the printrbot). Just loosen the screw by 2mm, drop the bracket in place, and re-tighten the screw.
Printed in 0.40 layer thickness and used 2mm skirts.