corners can snag on things when the bot is driving
around your living room. You can readily turn the square
into an octagon, hexagon, or pentagon simply by
lopping off the corners, like that in Figure 3. More
elaborate shapes don’t take that much longer to produce
— just a few minutes per cut, and you’ll make a better
robot. To create an octagon (eight-sided) base, cut the
corners off at 45° (see Figure 4). After cutting, use a
medium or fine grit sandpaper to smooth the edges.
FIGURE 5. The finished Phase 1 BeginnerBot — both the base
and the switch control panel.
FIGURE 6. This is the cutting and drilling layout for the
BeginnerBot base. Use 1/4” thick wood or plastic.
Cutting and Drilling the
Base and Control Panel
The first version of the BeginnerBot is composed of
two major pieces: the base of the robot and a control
panel that you hold in your hands. In later variations of
the BeginnerBot, this control panel will become a second
expansion deck, mounted directly on the robot.
Both are shown in completed form in Figure 5. I call
this Phase 1 of the BeginnerBot. Other phases (described
in future articles in this series), use the same basic
hardware parts, but in different configurations.
Figures 6 and 7 show the cutting and drilling guides
for the base and control panel. Construct the base out of
1/4” thick material, either 1/4” aircraft-grade plywood or
1/4” ( 6 mm) expanded PVC plastic. You can buy the
plywood at most any hobby or well stocked craft store;
get the expanded PVC from a nearby sign-making shop or
Cut the base from a 6” square piece of material. First,
cut the base to its 6” square size, then remove the four
corners as indicated. Don’t worry about getting the cuts
absolutely perfect. A fraction of an inch here or there
won’t matter. Construct the control panel from 1/8”
Use an electric drill or drill press to make the
holes as shown. The sizes of drill bits to use are
indicated in the illustrations. The exact location of
the holes isn’t super important, except for the four
near the center line of the base. These are for
mounting the two motors. Measure and drill these
very carefully, as misplacement or misalignment of
the holes can have a negative effect on the
operation of your robot.
FIGURE 7. This is the cutting and drilling layout for the BeginnerBot
control panel. Use 1/8” wood, plastic, or picture frame mat board.
Assembling the Motors
With the base and control panel prepared, lets
48 SERVO 08.2011