Extended Printrbot Simple Metal extruder fan mount with switch

thingiverse

I've included an extended model without a switch slot for those who want direct airflow over the aluminium block and don't need the switch. This remix is based on the blank fan mount and has been lengthened by about 10mm to make space for a switch slot and cool the aluminum direct drive assembly of the extruder. Behind the switch, I've connected a tiny basic circuit with a diode to prevent flyback damage to the bot when the fan is turned off. The cabling runs under the extruder and joins the rest of the extruder cabling back to the underside of the bot, where it is connected directly to the 12V pins on the power supply barrel connector. Cooling has been running very well even at higher extruder voltages! I had to increase voltage for the extruder to prevent skipping. Instructions: Printed on a Printrbot Simple metal using Slic3r. PLA, 2 perimeters, 30 infill, 0.3969mm layer height. I also printed with a heated bed at 65 degrees. Printed in about 8 minutes. The odd layer height is calculated to be perfectly divisible by the whole number of steps the Simple Metal's Z axis rod can move.