Duplicator 4 Sidefans

D4 Sidefan system.
This design uses the built in fans for cooling, thus no new fan is required.
If you have a single extruder version, print the LEFT duct and mount it to your printer. Also block the right side on the heatsink so that the air can only go left.
If you have a dual extruder version, then print both ducts and the microswitch toggle block. You need to mount the block on the right side extruder stepper motor to flip the microswitch as the duct needs some extra space on that side.
If you drill a 3mm hole in the heatsink at the same position as the hole on top of the ducts, you can use it to fasten the ducts.