Prusa MK3S extended fan shroud

thingiverse

This is my Prusa MK3S fan shroud modified a bit. I had trouble cooling the back side of objects that print. The design is symmetrical - the front overhang printed just fine but the back was melting. So, I took the original Prusa fan shroud, split it in two, extended its sides, and added some small plates to guide airflow away from the nozzle itself before making it solid again. To compare, load both this modified version and the original one into your slicer at the same time. The result was better on the same print, but only by a tiny bit. It seems that modeling tools are needed to make it work even better - I don't have them right now. UPDATE V2 14.04.2019 I thought some more about cooling. Prusa's stock design is probably optimized for maximum airflow. On the other hand, proper cooling of any specific spot should result from air speed on that very spot, not just general max airflow around the nozzle. So I made a V2 where openings are slightly restricted with additional plates. This should increase pressure and airspeed around the nozzle. After testing, it seems marginally better again. So V2 has smaller openings, which are more restricted at its bottom. This also results in a slightly quieter vent.