by Dave Calkins
ROBOGAMES
PREP:
Tetsujin! SERVO’s
Original Robot Challenge
Tetsujin — the ultimate robot
competition. When we build
other robots, we’re always
putting out time, money, and efforts
into the projects. More often than not,
we put our souls into the project. But
how often do we put ourselves into the
project? I mean that literally. No one
would enter a combat robot arena, or
risk riding in a Grand Challenge vehicle.
But Tetsujin takes it to the ultimate —
man and machine become one.
And to what end? Is this just something that we do as yet another robot
competition? Something that’s fun and
can win us medals or cash? Or is it
something more? Something that can
truly benefit man.
Not only could the ultimate
Tetsujin suit make you look like
Sigourney Weaver in Alien and help
you move those shipping containers
around the room, but the ultimate
Tetsujin suit can truly advance man.
How many crippled people could get
out of a wheelchair and back to standing in line at the supermarket?
Running to catch the bus? That’s
what Monty Reed of “They Shall Walk”
had in mind when he started building
walking suits.
Monty was injured in a parachute
accident, and the threat of never
walking again was very real. Thanks to
research and hard work on his part, he
68 SERVO 01.2007
did learn to walk again, but the dream
of mechanically assisted walking lives
on. At last year’s RoboGames, Monty
took up not only the weightlifting
challenge of Tetsujin, but also the
walking challenge.
To the untrained eye, it appeared
as though Monty was just walking
around the arena with a bunch of
metal and tubes surrounding him. Yet
his stomping and jumping were all
done with the suit. The dream is not far
off! The mechanics of making a ROBO-one walk and helping the lame walk
are essentially the same problems —
the major difference being that the
bones of the lame become part of the
support structure along with the metal,
and the motors are outside the
skeleton rather than in it.
Ah, but what’s this got to do with
RoboGames? Well, it’s one of the
premier events! Broken up into three
stages — weightlifting, walking, and
dexterity — Tetsujin is SERVO’s own
robot event.
Much too expensive, you think?
Well, Alex Sulkowski — winner of the
first $25,000 Tetsujin challenge —
bought all the parts for his suit for
$1,100. “Many parts were bought
cheaply on eBay,” says Alex. That’s
cheaper than the cost of the average
middleweight combat robot. Bryan
Hood, who was a high school student
during the first competition, said “our
suit cost roughly $2,000. Because of
the simplicity of the suit, there were
only three major purchases. These
included the pneumatics, the chromoly
steel tubing, and an air tank. Clippard
Pneumatics sponsored 50% of the
pneumatics cost for our team.” If a
high school student can do it, so
can you.
“The hardest thing about building
a Tetsujin suit is it requires understanding and integrating multiple disciplines
(mechanical engineering, electrical
engineering, bio-medical engineering)
while being extremely careful so that
you do not get hurt,” said Alex. “Most
of us understand one or two of these,
but few are masters at all three. This is
where team members who complement your skills come in handy. The
most difficult aspect of building a suit
is the control system that commands
the mechanical suit based on your
movement. The three main choices
for powering a suit are electrical,
pneumatic, and hydraulic. Each one
has major pros and cons that impact
the control system. On top of that, a
failure in the control system can result
in major damage to your body.”
Bryan adds, “Time, money, and
knowledge just about sum it up. As I
recall, I spent only about two weeks
actually building the suit and several
