— The Big Robot
by Gordon McComb
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FIGURE 1. The completed MadeUSA,
with base, motors, motor drivers, and
ring of 10 Ping))) ultrasonic sensors
(mounted on stands, also included).
Sure, I get to write about robots.
However, that doesn’t mean I always
get the chance to play with them.
And by play, I mean truly having fun
— the kind of fun a kid has when
given a new toy for Christmas.
Though definitely fun, my latest robot — the MadeUSA
from Parallax — is hardly a toy. It measures 18” in diameter
and weighs over 30 pounds when fully decked out. The bot
is provided as a do-it-yourself base (AYOM: Add Your Own
Microcontroller). I’ve tried it with an Arduino and a Parallax
Propeller, and both were easy to integrate.
The name MadeUSA comes from a play on words,
combining “Made in USA” with Medusa — the horrible
looking creature from Greek mythology known for having
snakes for hair. Take one look at her and you’d be turned to
I haven’t noticed any rock-forming tendencies while
working on my MadeUSA, but I’ve nicknamed my robot
“Big Brute,” and here’s why: Though Parallax doesn’t
38 SERVO 01.2012
mention it, this bot is strong enough to cart around a full
grown person. If nothing else, you could use MadeUSA to
build a robotic golf cart for your Great Dane. Yeah, that’s
one big dog!
It All Started With a
Piece of Wood
The original MadeUSA robots were made from high
grade plywood. Now, Parallax manufactures their big bot
out of a 5/8” thick slab of machined high density
polyethylene (HDPE). A completed MadeUSA kit — with all
included trimmings — is shown in Figure 1.
A computerized cutting mill shapes and forms the main
deck of the MadeUSA. Though a very strong plastic, HDPE
is known for being easy to drill. That makes it simple to
customize your MadeUSA with your own accessories. The
base is cut into a circle, with openings to make room for
the two high power motors (see Figure 2). The motors are
new automotive power window actuators, and have got
plenty of torque.
Smaller holes are pre-drilled for a ring of 10 Ping)))
ultrasonic sensors. These sensors attach on custom stands,
and are placed evenly around the circumference of the
MadeUSA base. I imagine that it’s the Pings))) around the