Air duct for 40mm fan

thingiverse

Chinese 40mm fans often have inadequate designs, featuring excessively large gaps between blades and fan ducts. Consequently, when used on thin air ducts, they prove to be inefficient due to the tendency of air to recirculate through the gap between blades and fan duct. To address this issue, a small cover can effectively mitigate opposite airflow. Trying it is straightforward: simply print the cover and then manually inspect air flow behind the fan with and without the cap in place. Print Settings: Printer: MPCNC Rafts: No Supports: No Resolution: 0.26mm