Designing and Building a
Part 4
ROBOT from
SCRATCH
In this series of articles, we
have worked our way through
the complete design phase
of building a robot. Starting
with “I want to build a robot,” we
developed a goal and created
a set of design specifications.
We next brainstormed and
used decision matrices to
decide on a combat robot with
a horizontal bar spinner as
the weapon, much like an
upside-down lawn mower.
Next, we chose a frame type
and the components along with
determining the ideal layout.
We completed the design of
the robot and learned some
tools and techniques that can
be useful when building a
robot. With all of this done, we
can now build the robot! In the
next few sections, I have
outlined the actual building
process of the robot.
by Brian Benson
Frame Construction
I started by manufacturing the frame because it is arguably
the most important part of the robot. Using our CAD model
as a reference (shown in Figure 1), I determined how much
material was needed. I ordered 36 feet of 3” x . 5” 2024
aluminum bar stock, so that I would have enough material for
two frames (plus a little extra). My first step was to spray
down all of the metal with layout fluid so that I could mark
where everything needed to be cut. Using calipers, a ruler,
and a scribe I marked each cut. I then used a handheld
Sawzall to cut the bar stock to appropriately oversized
lengths. Next, I used the mill to cut everything to its exact
length. With that done, I was able to then lay out the
frame as shown in Figure 2.
The next step was to drill the holes that would allow me
FIGURE 1. The robot’s completed design is
shown in a CAD rendering.
38 SERVO 06.2008
FIGURE 2. All of the aluminum is cut to size
and ready to be drilled and tapped.
FIGURE 3. One of the frame rails
has the through holes drilled
and countersunk for the screws
that hold the frame together.
