Figure 14-2 shows our mechanism in action. Rotating the steering arms makes the entire vehicle turn. And obviously, to turn, the vehicle needs at least one more axle, as Figure 14-3 shows.
In Figure 14-2, the rack gear is a specialized piece (#2791) that is slightly elastic, allowing it to bend to stay mated with the round pinion gear as the steering wheel turns. The pinion gear can be used with other gears, but we'd have to compensate for the rotation of the steering arms. Figure14-4 illustrates the problem