untitled

2. Drill holes for the 6-32 screws used to mount the castor, as shown in
   Figure 13-29.
   Use the base of the castor to guide you when marking the four holes you
   will drill in the chassis box to mount the castor.


3. Mark a location about an inch to each side of the castor and drill
   holes with a 1/4" bit to feed the wires to the motors and sensors, as
   shown in Figure 13-29.


4. Using a mending brace to mark the four holes you will drill in the
   box to mount the motors, drill holes for 8-32 screws, as shown in
   Figure 13-29.


5. Attach the castor to the box with four 6-32 screws and nuts, as shown
   in Figure 13-30.


6. Attach the motors to the box with two 8-32 screws and nuts and one
   mending brace for each motor, as shown in Figures 13-30 and 13-31.

Holes for feeding wires Screws for castor Screws for motor mounts

Figure 13-29:
The inside
of the box
after holes
have been
drilled and
the motors
and castor
are
mounted.

Chapter 13: Sensitive Sam Walks the Line 333