Cardan / Kardan

Hello, I made this model of cardan while working on big RC model of a heavy equipment vehicle. It has been in use since I did the drivetrain. 
We tested it by pulling. It managed to pull my classmate sitting on a wheelchair (he weights 105kg) The model has 16kg of weight so the tires don't slip. (everything except axis and bearings was 3D printed. It shocked us. All gears and the cardan survived without damage. 
This is a cardan we used. 
It's printed from separate parts for easy assembly and for it to be stronger.
you can make as many parts as you want and create a snake lol. 
It has sufficient mobility. 
the parts are locked by the outer ring (like on the photo).