This is a design for an electric ducted fan powered football.
In addition to the printed parts, this football requires the following:
-a 70mm fan (left handed version)
-an edf motor no larger than 28mm od
-a shaft adapter to fit the fan onto the motor
-a 40- 80 amp speed controller
-lipo batteries. I used 2 1000 mah 3s batteries wired in series and placed on opposite sides of one another to balance the weight
-a pwm control signal. I am using a servo tester but a microcontroller/accelerometer combo would be better for detecting throws and catches.
-a method of attaching the components inside of the shell. I packed them in with bubble wrap and tape.
total weight: 25 oz or less
A WORD OF CAUTION: THIS THING MIGHT BE DANGEROUS AND IS NOT A TOY! Build and use at your own risk.
This device consumes a large amount of power and has components that spin at extremely high speeds. Safety glasses and protective gear are advised.
Crash survivability has not yet been tested but I predict that it is extremely low. I would also avoid catching this with anything other than a fishing net at the end of a 10 foot pole.
Here is a bench test video of the edf unit:
Glue the football tip onto the football inlet using acetone.
EDF unit fits snugly into football inlet part.
Attach the football inlet part to the football exhaust part using tape or a better idea. I used velcro pads which double as grip elements.
The halves can be bolted together using the internal ribs as well. Small holes would just need to be drilled in the football exhaust part's exterior shell for access to the bolts.
Distributing the weight to make it nose heavy will help with stability.