During the summer of 2016, I worked at Origin Base, the first makerspace in the Middle East. ZeroOhm Electronics Company was hosting a drone racing competition in which one of the design requirements was for the drone to complete a flight cycle before releasing a parachute. They contracted my coworker and I to design an emergency reeling system that could be used to pull in the ejected parachute if it hovered too close to residential buildings of clusters of people. This was the final version of the system which went through many iterations over a month.
Initially, we iterated on prototypes, starting off with a large DC motor, and laser cut gears that would reel in and out fishing line attached to the drone.
The acryllic gears shattered at 200 RPM so I found some extra steel gears by the lathe, drilled holes in them to secure to the fishing reel spool, and tested the prototype with the 12VDC motor and a large lithium battery in the desert. It worked well but using gears off of the lathe wasn’t going to be a viable, longterm solution.
Instead, I bought v-pulleys from the local souq and laser cut 1/2” thick acryllic mounts to secure the v-pulleys to the spool.
I then secured the v-belts to the pulleys using a 1:3 ratio between the drive and driven pulley to maximize torque.