MegaBee V2 Coanda Duct Rev2 (Fits MegaBee HD)

thingiverse

UPDATE: I got tired of keeping the TPU in line, so I went to polycarbonate and made some key changes for Rev 2. Anyone wondering where I'm getting these design principles can find them in a couple of white papers (check out the PDF files). 1) Shrunk the gap down to .01 times the prop diameter 2) Refined the inlet duct radius to .13 times the prop diameter 3) Moved the flow separator ring away from the wall by .17mm and added an exiting radius below. You may now want to print this with supports 4) Enlarged the footprint area surrounding the two mounting holes. This solves some issues printing thin walls in PETG or PC. These have a slightly larger cross-section, but they're also going to allow you to clamp down harder with your fasteners, which will help keep the ducts straight 5) Also including version with no stiffening ribs This is a duct for the MegaBee that was designed around the Gemfan 3" prop on BH 1407 motors. The gap is now .030". The duct features a 5 degree divergence angle on each side for total angle of 10 degrees. It also features a very small step toward the trailing edge that is meant to help the Coanda flow separate from the surface for a more downward-directed exiting stream. This remains untested.