Traxxas TRX4 Chain Drive, Track Drive, All-Terrain Traxx

I have developed a chain drive for Traxxas TRX4 RC cars, which can be almost completely 3D printed. All you need are a few ball bearings and M3 screws. The drive train is fully functional and has already been tested extensively (in snow and mud).
 

Print:

The chain must be printed from TPU. The rest can be printed from PLA or PETG.

Ball Bearings: 

4 pieces 27x20x4

4 pieces 15x21x4

40 pieces 19x6x6

note: The anti-twist part (Verdrehschutz) is different for each drive wheel. And note that the pieces on the left and right are mirrored (except the chain, spacers and gear.). I have already included this in the download models. The M3 screws can be screwed directly into the parts (do not overtighten them).

I spent around 30 hours designing it and have already tested it for many hours. The design was tested on different TRX models. I hope you have as much fun with it as I did.