Hello all. I am building an extruder to fit on a 6050 engraving/milling machine and designing it myself for this purpose. Almost true to reprap as most of the components are being made on the milling machine. When designing the hot end I am wondering about the function of the the fan; is it to keep the outside surfaces of the hot end cool, or is it to blow warm air down onto the work? If it isby robert46 - General