Mini Sumo

Some Mini Suno competitions allowed the Lego robots to participate, if they obeyed the 10×10 cm dimensions and 500 g weight limit. I have built a couple, but the dimensions were a bit too restrictive. So, at LRGoAA, we decided to make our own Mini Sumo competitions where the dimensions were 6×6 inches and two pound weight.

Robots at ChiBots 2006


This was a mechanical robot built after ReaktorII. A lever would start a small motor that turned a bunch of wheels to create a 5 seconds delay and activate one of the bumpers (left, right or both, selected by me before the match), that would start the other side’s motor. The robot would spin in place, waiting for the collision with the opponent, but keep rotating until the other bumper would engage and drive straight pushing the opponent out of the ring. Of course, the robot would follow, but the first one out loses. Pretty cool, huh?


This robot used a custom microcontroller brick for Lego, built by me. Two Lego light sensors for edge detection and a Sharp IR sensor for opponent detection. Did not perform as expected.

Robots at LRGoAA Mini Sumo:

I had 4 robots at this competition… Borg Cube, US Blade, Big Kahuna and Nemesis. Here they are:


This time I built Borg a bit bigger and I could make a complete cube. It performed better and it was a hit.


Fast, powerful, with the Ultrasonic sensor it was unbeatable. Blade would have won the event, but in the last minute I decided to let the organizer win, so I disabled the Ultrasonic sensor. He put so much effort organizing the competitions over the years that I felt he deserved some sweet retribution. In the final melee, Blade cleaned out the ring no problem.


With a bigger battery box on top, the robot would do wheelies for the laugh of the spectators, but managed to stay up most of the time.


This robot was inspired by a prototype of the event organizer. The idea was to use pneumatics to lift the opponent and push it out. The robot used LIDAR to detect the oponent and a Touch sensor to trigger the lifting arm. An automated compressor would pump air in 2 tanks and a motor would switch a valve to extend 2 big cylinders. Didn’t work as good as the original robot, called Aliens (the builder didn’t remember the name of those exoskeleton loading machines from the movie).

Pictures from the competition:

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