A cooling fan for the new RepRapPro Mendel X carriage which holds up to four hotends. I found that a nozzle restricts the airflow too much and this open arrangement works better.Print one of each part. Put a M3x18 or longer bolt through the two parts to create a joint. Use M3 bolts to attach a 40mm x 40mm x 10mm fan. Attach to the X carriage using two M3 bolts with washers and nuts. Angle the fan so it is pointing down towards the hotend and tighten the bolt at the joint.