Build Your Own Combat Robot

FIGURE 2-6
A robot being
repaired between
matches at a
BotBash
tournament.
(courtesy of
Andrew Lindsey)
Design for Maintenance
Chapter 2: Getting Started 31
Part of the whole design process for combat robots is the design for maintenance.
In competition, you have about half an hour to make any repairs to the bot. This
really isn’t a lot of time. So you must design your bot to allow for rapid replacement
of parts. This usually means there are more bolted-on components than
welded-on components. You need to have quick access to the electronics and batteries
so they can be replaced or recharged in a matter of minutes.
Wheels should be designed to be replaced between contests because a lot of
weapons and hazards will destroy the wheels. If you break a chain in the transmission,
then it should be quick and easy to move the motors to replace the chain and
retighten it back in place. The components inside the bot should be laid out in a
manner such that you don’t have to remove a lot of parts just to get at whatever is
broken. The design should also allow for accessibility to the components. You will
need to have room to get your hands and tools inside the bot. Think about the
length of a screwdriver, or the length of a wrench. When you are designing the bot,
imagine yourself having to fix it quickly, and then alter your design for that. This
will require a little up-front thinking. The last thing you want is to be disqualified
because you didn’t have enough time to replace a dead battery. Of course, this is another
one of those things that you may have to compromise on. Some of the top bots
are difficult to work on. In a design like BioHazard’s, for example, the low profile
and small internal volume of the bot make things hard to repair. BioHazard is held
together by 700 screws, so getting inside him requires a lot of work with the electric
screwdriver before repairs can even begin.