“This Sumo Bot is a Scream”

Sumo Bot Entry for 8th Grade NYS 2010-11 Science Olympiad by Justin Fisher

Screaming Locust is dual-motor remote-controlled tank-style sumo bot featuring an Arduino microcontroller controlling two high-torque motors with orbital transmissions. Built for low speed pushing its custom motor shield uses a combination of 3-volt relays and fast switching transistors to provide variable speed adjustment and low heat characteristics while battling opponents. It is powered with eight nickel-metal hydride cells, and remotely controlled with dual Wii Nunchuck remotes for simultaneous pilot and co-pilot operation.

In keeping with tradition, the Screaming Locust’s extruded aluminium front bumper and aluminium chassis provide low-weight and high-strength and act as the bot’s main heat sink. The narrow chassis and oversized 3.5 diameter soft rubber tires allow this bot to run inverted.

 At 3.66 lbs the Screaming Locust is a formidable opponent.
Screaming Locust top side view with major features

Taking almost 12 months to make, the Screaming Locust is built to push.


  • 2 high torque symmetrically balanced motors with locked stopped position and orbital gear transmissions
  • Welded and threaded aluminium axils with direct driveshafts
  • Nickel-metal hydride rechargeable cells
  • On-board ATMEL ATmega328 microprocessor in Arduino Duemilanove configuration
  • 2.4 Gigahertz wireless communications with 433MHz sideband
  • Two sided operation
  • Rugged hand crafted aluminium chassis
  • Custom power switch cover imported from china
  • On-board radio for tunes
  • Relays and fast switching transistors with electrically isolated left and right channels
  • Remote control operation with Wii nunchuck
  • Dual 100+ decibel sirens
  • Practice golf ball for single third wheel.

Special thanks to

  • Arduino –
  • Adafruit – for their parts and tutorials
  • Tod Kurt – for his instruction and inspiration
  • Gold Coast Hobby for motivation
  • Dr. Wolf, Mr. Lee and Mr. Maier – for their sponsorship
  • Paul Kurtlando – for his battery advice
  • Jose B. – for his expert TIG welding

Parts, software and help from Arduino, Mouser, Black & Decker, ThingM, Adafruit, Digi, ATMEL, TI Sparkfun, Fun Gizmos, Radio Shack, Duracell, ST, Seeed Studio and others