Robot Building for Beginners, Third Edition

CHAPTER 24 ■ BODY BUILDING

Carving Out a Window in the Container Lid

The Ziploc container comes with a blue lid. Technically, the robot works fine without the lid. However, the

lid looks nice, adds structural stability, raises the sensors up a bit for a better view, and catches any robot

parts that fall out during operation (*gasp*).

Be sure to firmly tighten down each nut. When the robot is turned over to follow lines, the nuts are
facing the ground. Therefore, if a nut is loose, it’ll eventually fall off. If desired, you can purchase anti-
vibration nuts with built-in nylon centers, such as McMaster #90715A005. Or, you can install an additional
nut on top of the first nut. These are called jam locknuts.

Drilling Holes for the Trimpots

The final line-following circuit has two trimpots, one for headlight brightness and the other for balancing the
left and right pairs of sensors. With the circuit board in place, drill the necessary holes to be able to adjust the
trimpots with a small screwdriver (see Figure 24-30).

Figure 24-30. Tiny holes drilled into container front to allow a small screwdriver access to the headlight

brightness and sensor-balancing trimpots

Figure 24-29. Close-up of nutdriver tip