This extremely large and powerful ducted fan was designed and built primarily for powering a jet go-kart, but it has an array of other applications including scooters, boats, or R/C aircraft. Using two independent rotors, this massive fan has 8 blades on the first stage and 9 on the second stage. This difference in blade number dampens blade-on-blade interference noise making it slightly quieter during operation than a traditional contra-rotating propeller. 

Download 3D files: https://www.thingiverse.com/thing:6810086

This 120mm EDF is an extremely powerful fan that produces huge amounts of thrust. It requires a powerful electric motor that can produce both high speed and high torque. With the right motor, this EDF can produce up to 6Kg-10Kg of thrust. I have been able to get 4.2Kg of thrust with an 800kv motor on a 10 cell lipo, but this fan was designed to accommodate motors that are an order of magnitude more powerful than what I have tested. 

Download 3D files: https://www.thingiverse.com/thing:5895896

This extremely large ducted fan was designed and built primarily for powering a jet scooter, but it has an array of other applications including go-karts or R/C aircraft. Styled after the Rolls-Royce Ultrafan, this absolute unit of a fan has 18 interchangeable blades and room for a powerful motor. 

Download 3D files: https://www.thingiverse.com/thing:6438372

This oddly specific thruster is the result of trying to optimize a smaller version of my other EDF designs for use in an R/C jet. Designed after my very successful 120mm design, this 90mm variant has a very high thrust-to-weight ratio and is meant to be firmly glued into a square foam-core fuselage. Intended for printing in light weight PLA, it has several ribs for rigidity, yet thin enough walls to keep weight down. 

Download 3D files: https://www.thingiverse.com/thing:6592934

This gigantic ducted fan was designed for and used in a go-kart called "Green Lightning" but it has an array of other applications including other vehicles or R/C aircraft. It was built with a combination of 3D printing, Kevlar composites, and re-used materials. As the largest ducted fan I've created, it has plenty of thrust to propel the go-kart Green Lightning to terrifying speeds.

Download 3D files: https://www.thingiverse.com/thing:6462513