Thank the author a lot for making the Robak 2 project. I implemented wifi control, low latency with WebRTC, with camera could turn around using Rasberrypi Zero 2, servos, and a 3d print pan tilt module I designed. I learned a lot from starting with Robak2.

This design aiming for low speed, and higher torque. I don't like these RC car run fast, very dangerous for people, kids.

You will need:

3x M3 8mm (for connecting 2 case together through the “enc” file)

1x M3 12mm (Motor)

1x M3 16mm (Motor)

4x M3 nuts

1x 3mm rods 32mm length (for the 26_10 gear)

2x 3mm rods 35mm length (for the 34_10 and 30 gear)

I use eSun PLA+, these rods should fit tight to the case.

The rod is stationary, the gears will rotate on these rods.

Add some grease to the centre hole and teeth of the gear,  that will make it run more silent.

Powerflow:

motor_10 → 26_10 → 34_10 → 30 → driven_30

These herringbone gears would be tricky to assemble