Bragging rights are not exactly what [Jeremy Fielding] has in mind for his DIY dynamometer ... calculate the power output of a motor: speed and torque. A magnetic tachometer does the job of ...

[Tom Stanton] wanted to see if supercaps have any practical use on e-bikes, and built a DIY ... motor for the bike, using 3D printed formers for the coils and an aluminum rotor with embedded magnets.