An extruder mount replacement for the plain vanilla prointrbit (not LC) which includes a 40mm fan mount. It is a two part device which is box like with a 32mm opening at the bottom for the printer nozzle and airflow.Initial versions had the fan sloping 25 deg so it could be used without the "lid" part but this is difficult to 3D print. I have included the orginal in the SU file but not posted .stl for them ATM.The design is a bit heavier than it needs to be.It is possible heat build up could be problem if the fan is off for extened periods with the hotend hot. The thing doesn't need to be air tight so extra ventilation holes could be added.The fan worked too well and I had to partly cover the intake to tame it down. Some tuning it likely for changes in room temperature, filament, layer height and the size of the print.Can be 3D printed on printrbot. The small screwholes are intended to be tapped to M3 but the holes may print too large on some printers and need bigger screws or filling in in some way.The cable access hole has bit of support material which needs to be removed - be careful with this - if you use side cutters you may crack the main shell (I did) - try to twist it out with pointy pliers. The lid part would probably hold on just fine using a rubber band. It is mounted the same way as the orginal part.Test patterns such as the one shown in the image can be found here. http://www.thingiverse.com/thing:23965