Its a very simple & stupid Robot with a handmade sensor . All of the things you need to make it , is easy to gather for example from internet shop : RoboChip.ir
Step 1: Connect Gearbox Motors
Pictures are very clear . You can see & buy Gearboxes & Wheels + Armature motors in this link .
Shape the paper clips like a Bug antenna & connect it to the tip of micro switch with a wire-shoe & cover it with a small temperature cover .
Step 3: Connect 2 Battery Holder
Its simple with screws .
Step 4: Stand for Sensors
Step 5: Connect the Power Switch
Connect the power switch with a adhesive stick to the body .
Step 6: Power Circuit
Its very simple . We want 3 & -3 volt to CW & CCW rotating for 2 motors .
Step 7: Sensors & Motors Circuits (wiring)
Its very clear to understand . 0v connected to power switch .