Fan Duct for Ultimaker UMO+ (Modified "Tapir")

thingiverse

I wanted better airflow from my Ultimaker Original Plus's (UMO+) single fan, which was being blocked by its standard sheet metal duct. This resulted in poor cooling on one side of prints, making overhangs and bridging with PLA not as good as on the other side. The Ultimaker 2 and later models addressed this issue with two smaller fans that directed air from both sides for more even cooling. I could have adapted two fans and dual fan ducts, but I wanted to try improving performance with my existing single fan. Additionally, I was concerned about blowing out my electronics if I used the wrong fans that drew too much power. This led me to try the "Tapir" fan shroud on Youmagine by nhfoley. Unfortunately, it was designed for an earlier version of the Ultimaker than mine (the regular UMO) and wouldn't attach without modification due to differences in printhead design. I created a modified version of nhfoley's great design, which attaches to the printhead aluminum frame from underneath using two shorter screws instead of clamping onto long screws. M3 x 10 mm long screws were used for this purpose. The fan was attached to the duct with two original plastite fan mounting screws. The result is significantly improved overhangs and bridging on all sides of prints. Before and after photos of the "benchy" print in PLA show noticeable improvements, especially at the top of the cabin windows and other areas. To ensure that this fan duct doesn't warp or sag over time, I recommend using a high-temp PLA - the type that's dishwasher safe. I added Kapton tape and aluminum foil tape to protect it from the heater block, but I'm not sure if that's necessary. You should cover the screw holes with some foil tape so that no air leaks out. This upgrade is much simpler and cheaper than going the dual fan route. It has worked so well for me that I haven't bothered with a dual fan even though I eventually bought all the parts to do that.