Ihave had many people ask me over the years for ideas and
help in building large robots. There is enough material
available about experimental robot construction to fill a
bookcase, but I’m going to give a brief synopsis in two parts.
I’ve written about large bots in SERVO and I’ve built them for
fun, movies, promotions, and other purposes. I really enjoy
the challenge of designing and
constructing robots that are
the size of people.
I featured a large
robot built by Jim Hill of
Covina, CA in an article that
I wrote for Popular
Mechanics back in the mid
80s. Jim — who worked
for a car dealership — used
68 SERVO 07.2004
by Tom Carroll
automobile components, and surplus store parts to build this
remarkable robot, which he named Charlie. Charlie had the
most unique arms — their motors were hidden inside the
robot’s body; Jim ran flexible rotating shafts to surplus
aircraft “flap” linear actuators to move the various joints. He
used automotive electric seat motors that already had the
flexible shafts attached. This early 80s robot would be
amazing even today. You, like Jim, can easily build the robot
of your dreams.
Different people have told me that almost all of the kit
robots that they’ve seen seem to be for small robots — those
that can easily run about on a tabletop. Well, that’s easy to
understand, as the smaller robots are less expensive and
easier to construct. It could be said that large robots are just
like small robots, but have higher powered drive circuitry and
larger structures. The rest is about the same in both.
Many robot experimenters just want to progress to
something a bit larger — somewhat closer to human size.
Anthropomorphic (in the form of a human) robots have been
the goal of Sony, Honda, and other Japanese manufacturers
for many years; that interest has now drifted over to the US.
There are many books published on large sized “combat”
robots, but most of these don’t seem to cover much on
robots that are not destined to bash an opponent to bits or
be bashed in the process.
In this two part article, I’ll discuss some various shell
materials and methods of mounting the pieces. The robot’s
internal structural methods will be highlighted before we get
into the “guts” of the robot. We’ll look at the pros and cons
of various joints for the body and appendages, including
some simple ways to maximize arm efficiency.