This is a hitch assembly I designed for a 1/16th scale RC car. The exact car and trailer I have are:
RGT 136161 1/16 2.4G 4WD Rock Crawler: https://www.banggood.com/RGT-136161-1-or-16-2_4G-4WD-Rock-Crawler-RC-Car-Off-Road-Truck-Vehicle-Models-p-1695005.html
WPL Trailer Set For WPL B1 B24 B16 C24 1/16 4WD 6WD RC Car: https://www.banggood.com/WPL-Trailer-Set-For-WPL-B1-B24-B16-C24-1-or-16-4WD-6WD-RC-Car-Parts-Green-or-Blue-or-Yellow-p-1364716.html
All three parts are straight forward to print. Any material should work fine. The screw that holds the hitch onto the trailer comes with the trailer, so the only parts you need are qty3 M3 bolts. a 6mm long m3 bolt is perfect for the hinge assembly, but a longer bolt would just stick out some.
I attached the .step file to make it easy to modify for other RC cars and trailers.
The author marked this model as their own original creation.