MK2.5s - MK3s fan shroud modification...

thingiverse

3-19-2020 NEW Version uploaded V2 is a newer version with a bit better air flow. This is a "remix" of the fan shroud from Github. The one that ships with the printer/update kits actually allows too much air to hit the hot end and can cause a thermal runaway. For a while I got by with turning the fan speed way down, but you can only go so slow. So I found the model on Github and made a tweak to the central air flow, it doesn't stop it, just lets less through the center and more at the part. This and a silicone sock allows me to use 60% fan without thermal runaway. So I call that a success. Note: Please print in ABS like Prusa suggests. Since I have the sock, I'm trying mine in PETG to see how well it lasts. Follow up: Even with the sock, PETG was getting too hot. I've printed a new one in ABS, and attached pictures. Still working well, and I've had the fan up to 80% without a thermal runaway.