Reptile Cloud 149 duct for Gemfan 5 bladed prop

thingiverse

This duct design started as a replica of the Reptile Cloud duct. Then the inner diameter was reduced .5mm at a time to find the diameter which just clears the Gemfan 5 bladed prop. Early versions of the duct used melt-in inserts, but these are hard to position precisely. This led to distortions in the duct that interfered with the props. A tighter diameter fit was achieved by switching to M2 nuts embedded in the print. Tabs were added to the exterior so two ducts could be connected when installed on the Reptile Cloud 149hd frame. This made the duct assembly much stiffer. Connect with a M2x6 screw and M2 nut. When looking at the side of the duct pair, the tab on the left duct is toward the outside of the quad. Then, small changes to the height, inlet curve, and wall thickness were made to reduce the weight of the ducts to match the COTS Reptile Cloud ABS ducts. The base was kept slightly wider to help the duct adhere to the printer bed. When printed with eSun PLA+ filament, these ducts are very tough. I've included files for the version with tabs for mounting to the Cloud 149hd frame, and also a version with no tabs, for mounting on frames with different motor spacing. I found that the tighter fit to the Gemfan props results in slightly extended flight times over the stock ducts. Plus, you can make them any color(s) you want. Credit to FPVCycle for the dimensions of the mounting hole pattern.