Summary Extruder stepper motor temperature taken after 1 hour of printing with all the covers off and door open. Same model printed for each test at layer 20. Original stepper motor platform. 55-58c fluctuating. *Stepper motor platform modded with air holes. 47-50c fluctuating. Stepper motor platform with inproved wind barrier sealing. 54.7 c steady. New wind barrier design. 48.7 c steady. New wind barrier design and **fan air flow reversed. 48 c steady. *Perforating the stepper motor platform seems to have made the most difference **Reversing the fan exhaust seems to make almost no difference. Instructions Be gentle with the stepper platform during removal of the support plastic. Straight forward design, mounts in original spot with original hardware. I added two screw holes to the wind barrier for the fan so the fan would have four screw instead of two. Screws are 3mm x 16mm socket head screws. Wind barrier has slots for an LED light strip that may or may not fit the original light strip. You will need a 3mm tap for fan screw holes.