clamking

thank you for your testings. many people just take it and don't give me any feedback. another possible reason is i modify the angle of outlet after i test it. the outlet is 120 degrees before and 80 now to reduce the volume. according to my simulation, the temperature of nozzle decreased by 10 degrees at least. but people in our group is still not satisfied ,they want more powerful cooling, so the turbo fan edition is already under working by an old man in our group.

make sure your nozzle is 3mm out of the duct. if you still couldn't get good quality, then give it up, maybe not suitable for your printer. a guy in our group uses the same nozzle like yours, he couldn't get better quality, too. i'm using a e3d nozzle.

use the curve in the fan datasheet,

Say goodbye to curling edges and ugly overhangs！ If your prints knocked over by your nozzle, try this fan duct. Up to 80 degrees overhang without any support structure! guys who don't konw fluid mechanics at all, please stop to design any fan duct. BUT EVERYTHING HAS ITS COSTS. Some sacrifices must be made. The printing length of x axis will be 25-35mm shorter. Use the slider extender attached. Recommend to print first one with few support, and use this fan duct to print another without support. fan duct design is not easy, the fluid won't flow as you wish. remember fluid always choose the easy way. boundary layer separation will always cause pressure loss fan duct is published here http://www.thingiverse.com/thing:1492821