This is a project to develop and host mini sumo robot builds and events, sponsored by the robot builders guild at It Begins in Brockport (https://ibib.us/) and led by myself.
In robot sumo two autonomous robots compete in a head-to-head match following the basic system of traditional human sumo matches. Robots are allowed no weapons, and are not allowed to intentionally flip each other. The sole purpose is a pushing match between the two robots to force the other from the arena.
Materials available here will include the parts list and instructions for creating and programing a mini sumo bot that fits the IBiB2040 class for mini sumo, along with competition rules and other material. The project is still in development in the Spring of 2024.
Event information for the Rochester, NY area can be found at IBiB under the Mini Sumo Robots project.
I will be happy to assist anyone who would like to build these robots or organize a competition, in my region (Western New York) or beyond. We will have a limited run of partial and complete kits available through IBiB. Please get in touch with me at bill@tinkerfarm.net if you are interested.
IBiB2040 Mini Sumo Robots
The goal of this class of robot is to provide a very inexpensive platform as an entry point into mini sumo events as well as an easily extendable platform for many kinds of robots experimentation. Purchased in small batches for club use, these robots cost about $30 each for parts.
Parts
Beyond satisfying the basic mini sumo requirements of a maximum of a 10cm x 10cm footprint and a maximum 500 grams weight, the focus of this design is using the Cytron Maker Pi RP2040 mainboard and keeping costs low. The parts detailed here are illustrated in the parts preparation document (below).
The Maker Pi board is based on the Raspberry Pi Pico processor and adds motor controllers and other functionality at very low cost. It can easily be programed in Python. Full manufacturer information can be found on Cytron’s site. The boards are available from many vendors, Newark sells them for under $10. The Maker Pi comes as a kit that includes connecting wires required by this project in addition to the board itself.
Additional parts (widely available) include:
One 4xAA battery holder.
Two N20 6 volt gear motors. These are available in a variety of RPMs and torque ratings. Motors rated at 150pm or 200rpm seem to give the best results. These can be purchased with or without connecting wires pre-soldered.
Two 43mm*19mm wheels/tires with a 3mm D-hole for mounting to the motors.
Two VL53L0X time-of-flight (TOF) ranging sensors. These are used to detect and pursue the opponent. These are usually sold with lose header pins that need to be soldered.
Two TCRT5000 infrared reflective sensors. These are used to detect the edge of the arena. The plans posted here require the format shown in the parts preparation document, with the black detector block on the bottom of the module.
Hardware: The plans posted here use twelve 3mm*12mm Philips head bolts, one 3mm*12mm counter sunk Philips head bolt, and hex nuts for the bolts. Any hardware that fits is fine.
Ballast: If the builder wants to maximize the robot’s weight, 200 to 250 grams of ballast will be required for the 3D printed chassis. The plans posted here show the use of 4.5mm steel BBs (.177 caliber), which will easily fit in the ballast boxes in the design. Weight is weight, so many other types of ballast material are possible.
Tools: A Phillips screwdriver (or other driver that fits the hardware) and a small set of needle nose pliers are sufficient. A micro USB cable is needed for programing. Soldering gear may be needed.
3D printed chassis
A reference 3D printed chassis is provided here. It consists of four parts which will take several hours total to print. Details for printing can be found in the parts preparation document.
Note that a chassis does not need to be 3D printed to conform to the IBiB2040 rules, it can be made of any material.
Parts Preparation and Assembly
The parts preparation document includes illustrations and descriptions of parts and how they should be readied for assembly.
The assembly instructions document and illustrate the building of the robot once all parts have been prepared.
Software and programming
The robot is programmed in CircuitPython (which is pre-installed on the Maker Pi board by the manufacturer). It will require the Adafruit VL53L0X library to be installed by the builder.
Builder installed software will be needed for the robot to operate. Complete reference examples are still in development in Spring 2024, however a very crude drive and attack example can be found here for testing purposes.