Prusa MK3 cooling fan duct/shroud

thingiverse

I've been on the hunt for a more efficient cooling fan nozzle/duct/shroud combo for my MK3 with the new R3 head, but I just couldn't find what I was looking for. So, taking inspiration from some of the many improved fan ducts out there for the MK2 and other models, I decided to design one myself that would provide airflow from both the front and sides. Note that this design requires the fan to be mounted at 90 degrees instead of its usual 45-degree angle. I haven't conducted any airflow tests on this duct yet, but it does seem to improve the overhang capabilities of my Prusa i3 MK3. I'd love for you to test out the air flow and share your findings so we can optimize further. For the print itself, I used PETG with the settings listed below. With 100% infill, you might think it would add weight or printing time, but because of the duct's thin geometry, that's not the case. The orientation of the duct is exactly how it will be mounted. The slicing was done in Slic3r PE with "Detect Thin Walls" and "Detect Bridging Perimeters" enabled - everything else was pretty standard. With a layer height of 0.15, this print took me just under two hours to complete. One important note: don't forget to add a small washer between the upper fan mounting bolt and the head to prevent the fan from getting skewed.