Many years ago, I had an idea to build a 3D printed RC tank. It started out as a small tank, and has since grown into this huge and more complex tank. It currently consists of over 300 3D printed parts, all of which I have drawn in CAD my self. It uses two DC motors, each outputting force to a 27:1 gearbox (also 3D printed, using helical gears). The DC motors are controlled via two DC ESC’s, which are controlled by a small circuit board that I soldered. The circuit board have an Arduino Pro Mini and a nRF24L01+ 2.4GHz module to receive controller data.
Here are some pictures
And a video of some initial testing