CHAPTER 24 ■ BODY BUILDING- If you’re going to include LEDs in the tube, insert them now into the other end of
the tube and feed their Molex connector out the center hole. - Feed the Molex connector of the 68 cm taped motor through the wider end of the
tube and out the center hole.
At this point, there should be one motor on each end of the tube with the LEDs inside the middle of the
tube. All three connectors should be popping out in the center hole.
Insert the motors and tube into the robot’s container body and test the fit. To aid insertion, you can
push the motor on the wider end in all the way. Either add the washers and screws to hold the motors and
tube in place, or remove the motors and tube and wait until you have drilled the holes for other parts in the
container.
Adding the Switches and Battery Holder
Using the grinding stone accessory, grind suitably sized holes at the rear of the container for the power
switch and line-following switch (see Figure 24-21). Be sure to leave enough room between the switches to
install a 9 V battery and battery clip.
Figure 24-20. Motor’s Molex connector emerging from hole in middle of tube
Figure 24-21. Large hole ground out for power switch (upper left) and small hole ground out for line-
following switch (upper right)
The diameters for the holes for the switches depend on the sizes of the switches you choose. To avoid
removing too much plastic, drill smaller holes than you think are necessary and then test the fit of the
switches. It would be lousy to have to be gentle with your switches because you’re afraid they might fall in
due to holes that are too large.