robots under covers. People were
proudly showing their bots in detail,
and many teams were helping each
other fix their robots. This was
uncommon before 2006. I also believe
the tutorial helped to increase the
number of Brazilian teams who
compete, not only due to the technical
tips, but also due to the description of
our wonderful experiences at
RoboGames. Finally, the fact that we
won both a gold and bronze medal in
2006 also had a great impact. It
showed other teams that it was possible for a
Brazilian robot to win, even in such a tough event.
RoboGames also had an influence on the number of
categories in Brazilian hosted events. Since our attendance
at RoboGames, we added hobbyweight combat in 2007,
featherweight combat in 2008, and then followed by 3 kg
Sumo and hockey in 2009.
Since 2006, we’ve attended RoboGames every year. For
RoboGames 2007, we increased the speed of Touro’s drum.
We needed that extra energy against the increasingly well
armored bots. The width of the S7 drum teeth was
increased from 3/4” to 1” to take all the impact energy. All
hex screws were changed to flat or round head, so they
wouldn’t be torn off. We also built our first lightweight —
Touro Light (Figure 5) — using the same idea as Touro.
Figure 6 shows one of our most exciting matches — Touro
against Sub Zero. In only our second year at RoboGames,
we went undefeated in both middle and light classes to win
two gold medals. It was a wonderful experience!
Even though our robots didn’t break, we’ve learned a
lot from the fights. We had to change Touro Light’s drive
motors after every match — using only two 775 motors was
not enough for a lightweight. After facing Pipe Wench, we
realized that it would be good for Touro if its drum was
reversible, to effectively work even when flipped over.
We also realized that our robot’s ground clearance was
too low, since it got stuck quite often. In Brazil, our arena
does not have to take the punishment of heavy or super-heavy bots, so its floor is very smooth (with seams no
greater than 1 mm). If you have a match right after The
Judge or Megabyte, several seams may have opened up.
We’ve realized that the bot has to adapt to the arena, and
not the other way around.
For RoboGames 2008, we decreased the thickness of
Touro’s top and bottom plates to gain a little ground
clearance. This didn’t solve the problem, but it did help a
little bit. Touro’s drum became reversible after changing the
weapon solenoid to a pair of Victor speed controllers. Touro
Light’s drive motor was changed to an 18V De Walt. This led
to the birth of our first featherweight: Touro Feather.
Touro was doing well until it got defeated twice by the
vertical spinner Professor Chaos. One of our main problems
was our 1” wide tooth which did not withstand a weapon-to-weapon hit while Touro was flipped over. Touro Light
Figure 7. Touro vs. Mortician 2009.
(Photo by Brian Benson)
didn’t do well either – its planetary gearboxes didn’t take
the higher power from the 18V De Walt, shearing the pins
from the last stage in two different matches. Touro Feather
had a very powerful brushless motor spinning the drum,
however, the drum’s v-belts were too rigid which prevented
the brushless motors from spinning up sometimes. The low
starting torque of brushless motors can be a problem if the
BESC (brushless electronic speed controller) is not well
In 2009, I released the English version of the RioBotz
Tutorial. I had learned so much at the RoboGames 2007
and 2008 events – both from other builders and from
broken parts – that the tutorial doubled in size, reaching
380 pages. You learn a lot from these types of events. It’s
like drinking water from a fire hose sometimes, so be ready
to take several pictures and notes.
For RoboGames 2009, we increased Touro’s S7 drum
tooth width to 1.5”, using a new drum with a higher
moment of inertia. Both Touro and Touro Light’s drums
featured a single S7 tooth, balanced by a tungsten
counterweight flush with the drum. Touro Light’s drivetrain
was upgraded to a pair of De Walt power drives. Touro
FIGURE 8. Touro Light vs. Come to Mamma.
(Photo by Brian Benson)
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