Two unique things about this solution are that a) the stepper motor rests directly on the slider plate - this gives the needed clearance from printer head tip beyond the beam the slider rests on, and b) the cooling solution is a less noisy axial fan of higher volume of air at lower pressure (and lower back-pressure which makes the noise).
I've tested the cooling with PLA at 300 mm/s top speed and was able to get very good over hangs up to just under 80 degrees slope.
The duct can be printed upside down with the faceplates for the 40mm fans on the build plate. It can be printed with supports to build plate only and without cooling. Note in the actual image if the duct, you'll see a drilled hole, this is for easier installation and tightening of the screw under there. You CAN install without that hole but it is a pain doing through the duct, I'd rather drill a hole and plug with tape (or not plug, the leakage likely isn't significant). Up to you.
Update: The motor mount has been stiffened.
The author marked this model as their own original creation.