I am attempting to make a useful and accessible motor using cheap, widely available parts and utilizing 3D printing as much as possible. Currently I am on my 5th version. The current version is an out runner style brushless motor with a single stator a two rotors.
The stator is three phases and toroidally wound around a 3D printed air-core. resulting in no cogging and no core losses. The rotors each contain a halbach array of N52 magnets stuck to an iron backing that is epoxied into the 3D printed halves.