MegaBee V2 Coanda Duct Rev2 (Fits MegaBee HD)

thingiverse

UPDATE: I got tired of keeping the TPU straight, so I went to polycarbonate and made some adjustments for Rev 2. For anyone wondering where I'm getting these design principles, I stole them from a couple of white papers (see PDF files). 1) Shrank the gap down to .01 * the prop diameter 2) refined the inlet duct radius to .13 * prop diameter 3) brought the flow separator ring out from the wall to .5mm from .3mm and added exiting radius below. You may now wish to print this with supports 4) Enlarged the footprint area surrounding the two mounting holes. This solves some problems printing thin walls in PETG or PC. These have a bit bigger 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.