J-head cooling fan mount 30 mm

This is simple fan mount for standard prusa i2 x carriage. I attach it with the same screws holding the extruder with the x carriage. It reduced filament leaks during extruder travel and retraction. It is directly plugged into power source so it works all the time.

V2 fetures improved air guidance. Now it should blow directly into j-head's cooling holes.