CHAPTER 6 ■ ROBOT LINE-FOLLOWING
At the other extreme, large robots are usually heavy, requiring larger motors to move. Large motors
need a lot of power, which leads to a bigger battery. To support all the weight, the body must be constructed
of stronger materials, which are harder to cut and drill.
Perhaps the best size for an amateur robot is around the size of a lunchbox. Plenty of parts fit those
dimensions, standard consumer batteries provide enough power, and plastics and soft metals have enough
strength for the forces exerted. Topping it all off, lunchbox-size robots fit well within the home.
This is not to say you’ll forever be stuck crafting small creatures. With the successful completion of a few
moderate designs, you can expand your work into the dimensions you desire. At that point, you’ll already
have experience with all of the robotic fundamentals, allowing you to concentrate on the unique obstacles
that occur with other proportions.
Seeing Sandwich
There are many possible designs for a line-following robot. I’m presenting Sandwich’s design because it
contains the fewest and simplest parts possible, while still being cool and capable.
All of the components are currently being produced, so you don’t have to use salvage. However, you can
choose to make a couple of the pieces yourself from raw materials.
This robot is named Sandwich because its body is based on a sandwich container. Even if you choose
a different shape, you can still apply the same circuit and techniques. Depending on the motors and
containers you have lying around, your robot may turn out looking very different but with approximately the
same line-following capabilities.
Examining Sandwich
At first glance, Sandwich may appear to be a very complicated robot (see Figure 6-8). That’s exactly the
impression you want people to have. Blinking lights, colorful wires, production-quality wheels, metal screws,
and a rounded case all add sophistication without adding much real work. Half of the battle is showmanship.
Figure 6-7. A palm-sized line-following robot