I love to watch at the filament deposit. I can stay a long time to see and enjoy the layer building up !!. Having a Tarantula with dual stock extruder, i need a fan duct that can cool both hotend but lets me enough clearance to have a look at filament fusion and layer construction. That is how the the "Fang Duct" was born...and no the "g" is not a mistake ^^, looking at Tarentula anatomy pictures, the duct designed looks like "Fang".
you will need 2 M3x16 screw,
It is design for fan 40x40
Dimension between the top surface of the X-carriage (acrylic part) and the bottom of the Fang Duct is 53mm. Full STL of the assembly is attached.
It works good for me ^^
print @ 0.1mm layer
If printed at 0.1, no support is needed if you have at least 3 perimeters, with proper cooling and slow speed when you reach the high angle overhang area, it will be nice enough to do the job.
print @ 0.2mm layer
At 0.2 you will need support, but be sure that NO SUPPORT are inside the duct, parameter should look like "from build platform only". it will be ok.
Personnaly, I have printed it with a 0.2mm layer up to 46mm and then 0,1mm to finish the print (i used 2 process with Simplify3D, i don't know if possible with other slicers)