It’s time to start building your robot. There are three basic parts that you need to build a robot: a power source, a brain (the PICAXE of course) and a means of locomotion (in the case of a roving robot). The Snap Circuits Rover is one example of locomotion. It has advantages and disadvantages.
It is a ready-made vehicle. In other words, you don't have to build a vehicle--it is already built for you.
It has two motors, one on the right side and one on the left side. Each motor is connected to the front and rear wheels by a series of gears (the gearing was added in to slow the Rover down rather than a need for extra torque) so that the right motor turns the right front and rear wheels, and the left motor turns the left front and rear wheels. In the first picture you can see the front of the rover as well as the gears that connect the left side wheels to the left side motor.
It is designed to have the Snap Circuits base plate connected directly to it. It is also designed so that power and motor control are easily connected with Snap Circuits jumper wires.
It has a battery compartment for six AA batteries to power the motors with 9 volts.
It is not designed to have attachments such a robotic grabber arm attached to it.
You must be careful to design your circuit so that you do not accidentally pass the 9 volts from the rover's battery pack through the PICAXE microcontroller since this will most likely damage the PICAXE.
Picture 3 source: http://www.elenco.com/admin_data/pdffiles/SCROV10.pdf