competition and our first drum bot. The plus side of
entering so many bots is that you are guaranteed
more fights and it reduces the chance that you get
knocked out early on. The down side is that you are
kept really busy both fighting and maintaining
All weight classes were very closely fought. In our
first fight, Surgical Strike fought It Stings — a new
drum bot from Florida. We were pretty confident
going into the fight since our large horizontal blade
has usually had little problems with drums in the past.
We got a couple of good hits in when our bot just
suddenly stopped working and was counted out. The
problem turned out to be nothing more than a
broken connector between the battery and the bot’s
Lesson 4. If something doesn’t
seem quite right, take the time
to check it out and fix it.
I recalled that the connector had not gone
smoothly together when I was completing and testing the
bot the day before. It had worked okay though and I had
thought nothing more of it. It turns out the spring section
of the Deans type connector had broken and fallen out so
that the contact didn’t make a reliable connection. It had
worked fine in the Safety test and in the test box just
before the match, but the hits had broken the connection
and killed all power. A new connector quickly fixed this but
it was frustrating to have lost for such a simple reason —
doubly so since it turned out we had already damaged It
Stings enough that it had to retire from the competition.
The lesson of fixing things when you know something is
not quite right would come back to bite us again later.
Pure Dead Brilliant’s first fight was against Misdirected
Aggression. The latter has what is probably the longest
Beetleweight blade in the world and far outreached the
blade on our bot. The fight started really well with PDB
removing one of his opponent’s wheels in the first hit. That
did not stop MA from shuffling around on one wheel and
with the blade still spinning dangerously. Andrew went in
for a couple more hits, then kept out of range until it was
apparent that the big blade on MA was slowing down.
Andrew attacked again and after a couple more good hits,
MA tapped out.
The effectiveness of that long blade can be seen in the
damage done to PBD (Figure 4) where the cut goes all the
way to the axle bearing. Nasty, but not fatal. The weapon
drive system on MA had failed and was not repairable, so
another bot was out of the competition.
Our next fight was with our new drum bot, Weta, God
of Ugly Things, against horizontal blade spinner
Traumatizer. Weta is actually a test bed for a new
Beetleweight kit I plan to have available in the summer. It’s
a fairly conventional design but with one new feature.
Drum bots often end up inverted — either through a hit by
an opponent or sometimes even through gyroscopic effects
— while trying to turn fast (this is called “gyro dancing”).
Once the bot is inverted, the drum is much less effective as
it can no longer throw the opponents up into the air. Weta
gets around this problem by using a reversible brushless
speed controller that can stop and reverse the rotation of
the drum in seconds. These reversible controllers are
designed for RC cars and once were very expensive, but
they’re now available from companies like Hobby City
( www.hobbycity.com) for less than $35.
SERVO 05.2010 45