I had some free time over the past couple days, so I decided to make a Strain Wave Reducer, more commonly know as a harmonic drive. The design I came up with mates with a Neo, has a 50:1 reduction, and is mostly 3D printed.
A Strain Wave Reducer have a couple advantages compared to more traditional reducers like planetary gearboxes, the main one being that they have no backlash. They also tend to be more compact and lighter as well. If you are curious how a Harmonic drive works, I would strongly recommend checking out THIS video as it does a far better job explaining it than I could.
The prototype I made was fully 3D printed out of PLA (mainly because I do not have the ability to machine aluminum at my house and did not have the hardware, like bearings, on hand). Although not super-efficient due to the higher friction due to not using ball bearing, it has preformed quite well using a drill as an input. If you were to use a stronger material, I am confident that this design, or one like it, would hold up quite well in a competition setting.
I have uploaded the CAD to Grabcad HERE.
As always, questions and comments are more than welcome!