Summary

This is a 40mm fan holder with a duct that wraps around the extruder to blow down on the extruded filament and the extruded part from 3 slots located 120 degrees apart around the extruder nozzle.

So far I've printed up to 1.5 hours without any noticeable heat problem.

My print had a few breaches in the hull which were sealed with super glue.

Instructions

VITAMINS:

6 20mm M3 screws

TOOLS:

Printrbot Simple
M3 HSS twist drill threaded bit Exact Thread
2,5 mm Allen wrench

OPTIONAL TOOLS:

3mm Twist Drill Bit
Rotary Tool
Round Needle File

INSTRUCTIONS:

Printed on my Simple using 0.20 mm layer height, 3 perimeter layers (probably more than necessary and 33% hexagonal infill which gave me a weight of roughly 15 grams.

Dependent on print quality you may have to drill out the two mounting holes with a 3mm twist drill bit in a rotary tool or reaming them with a needle file. Be careful not to overdo it, for stability you want an almost perfect fit. In my print they were a little large so check before reamint / drilling.

Thread the four fan mount holes holes. Be careful with the one that goes into the duct, you don't want to punch a hole in the inner wall.

Wait for the extruder to cool down before attempting to mount the duct!

Raise the print head enough to let the duct slide around the extruder.

Mount the tray extension with 2 20mm M3 screws replacing the original 16mm M3 screws..

Centre the extruder in the middle of the duct before fastening the duct securely.

Printrbot Simple 40mm Fan Mount with 360 Degrees Duct