This is my first pass at modelling a toroidal propeller for a light weight RC Plane. The inspiration is from the folks at MIT making a quiet drone prop.  This is a simple slanted circle design that is not optimised.  The plan is to learn from others such as “STRIKING FPV” who is pushing out and testing great designs for drones and make additional iterations to improve efficiency etc. 

This 140mm prop with 4mm shaft pushes out around 700g of thrust on a 2S LIPO on a 2212 2200KV motor. The prop actually expands at the higher revs so I would strongly encourage safety glasses are worn as this is likely to let go in a spectacular fashion.   

If you print this out and fly it I would like to know how you go!