Since the kit comes with a single motor assembly allowing the tank to only go straight forward or backward, I also bought the Double Gearbox from TAMIYA. It can be assemble with 4 different ratios: 12.7:1, 38.2:1, 114.7:1 and 344.2:1. I went for the 114.7:1 ratio since speed is not a necessity.
The tank kit is not build to fit with this particular gearbox so I had to modify the base plate to accommodate the support bar that came with the gearbox but that was meant for another kit.
I want to have an standard Arduino board running as the brain for this project. Since there will probably be a lot components to control, I needed to drive the motors using only 2 pins from the Arduino board. So, the next step was to build a motor driver PCB that would accept the inputs from the Arduino and take care of the rest. This was a perfect excuse to make my first homemade PCB. I'll get to that in the next post.