Shielded fan duct part cooling vent for Ender 3 CR10

thingiverse

The default Ender 3 (and other Creality printers) hotend fan assembly and part cooling duct has two problems: Not a lot of air flow by the part cooling fan, but a lot of parasite air flow by the hotend cooling fan. The first is bad for print requiring cooling (small size PLA...), though it somewhat compensated by the second problem. The second problem is bad for prints that require as little cooling as possible to avoid warping (large size PETG, ABS...). For the first problem a lot of simple solutions exist, e.g. the fan duct this thing is remixed from. But for the second problem, all solutions I found replaced the whole fan assembly, take a lot of time to print, aren't easy to print, tend to weight quite a lot and sometimes obstruct view to the nozzle, e.g. the Hero Me, Pets Fang... So here is a simple, fast to print solution: A little fan duct that directs the part cooling air directly to the nozzle while keeping the hotend cooling air mostly away. From what I learned manufacturing tolerances are quite large on the original hotend covers, so this thing might as well not fit for your printer. If that's the case, let me know and we'll see what we can do about that. Maybe provide multiple models with different sizes. Of course it has to be printed with supports, but only touching build plate, because it has a lot of flat overhangs. But the supports are easy to remove with a blade, because all are accessible from the sides. Oh, and I think it may not work with PLA, because it's very close to the heater block. I used PETG and it works just fine.