Build Your Own Combat Robot

308 Build Your Own Combat Robot
Research what supplies you already have on hand to do your building. What
tools do you own or have access to? Do you have space in which to build or have
access to a place to do the construction and testing? Do you have access to a machine
shop or know someone who does? How about a milling machine or lathe?
Check out the availability of time on the milling machine in your friend’s garage
or the willingness of a local metal shop to cut aluminum or steel to your specifications;
this will indicate what resources will be there when you need them. Local
machine shops might want to be involved themselves, and you might wind up
with a sponsor. (That happened with my team’s robot, Spike II. The machine
shop that did all the aluminum cutting and welding donated a portion of their services
in exchange for advertising and help redesigning a printed circuit board.
Yes, barter still exists today. If you have skills to trade for time on that milling machine
or access to the heli-arcwelder, you should go for it. Bartering cut down on
the expense of building our robot, and we made new friends and contacts.)
It definitely pays to look into the technical expertise that exists in your own
neighborhood. Radio Shack can supply electronic bits and pieces at a decent price.
Investigate what equipment—specifically, radio control parts—your local hobby
store can get for you. Hobby stores that cater to model makers (especially model
makers who build their own R/C planes, boats, and so on) often have a good selection
of speed controllers and other essential equipment. Be sure that you purchase
a speed controller that will handle the current you intend to pump through it.
Many contestants at early Robot Wars competitions fried their speed controllers
because they didn’t check this detail. As far as R/C equipment goes, my advice is
this: Don’t get a cheap radio. It pays to invest in a good-quality PCM or FM aircraft
radio set for ground frequencies. The aggravation you save will be well
worth the money you spend.
Step 2: Conception
After you’ve done all your research—gone through those parts catalogs, know
the rules, and are sure of the weight class you want your robot to compete in—the
next phase is coming up with the design sketch. You don’t need heavy-duty engineering
computer aided design (CAD) software to create a basic design sketch.
Our work was done on an artist’s sketchpad and on notebook paper. The average
builder won’t have AutoCAD on his or her home PC, and it isn’t necessary if you
plan a simple robot design.
The photographs of my lightweight entry Chew Toy (Figures 14-1 and 14-2)
show its simple design. Chewie is a basic robot—all the essential parts, such as the
motors, batteries, and major weapons, were not that hard to lay out and assemble.
The robot’s conception came out of the hypothesis, “If I could use only a surplus
store’s catalog to get parts to build my robot, what would I design?” In reality, I
use a lot more sources for parts. However, I was curious. Could I come up with an
effective design by pretending I was limited in parts availability?
As you can see, Chew Toy has a simple structure. It relies heavily on its 3.5-hp,
four-stroke motor and those rather evil sharp saws to do its battle damage. The