At this point, you have some wonderful motors that are only spinning themselves. In this chapter, you'll be introduced to a variety of wheels and some criteria to aid you in selecting a pair of wheels for the line-following robot.
Most wheels consist of two parts (see Figure 19-1). First, there's the tire, which is the rubbery part that grips the surface. Then, there's a sturdy core, which distributes the motor force and retains the wheel's shape.
Figure 19.1. An ordinary wheel with the rim partially pulled out
The portion of the tire that usually contacts the ground is called the tread. The sidewall is the portion ...