This tutorial will show you how to build Vivus the Robot, an autonomous, self navigating little robot. You can get the Vivus the Robot Kit from the BW Science Labs Store here.
Step 1: Chassis
Step 2: Motor Gearbox
Here are the side and top views of the gearbox. There are a few ways to piece this together, I recommend that you work from left to right and take it slow.
Step 3: Power to Microcontroller
NOTE: you may have received a different type of battery holder, where the wires are built into the box. This works just as well, but you many want to wait until the end to screw in the black and red wires.