Overview
This is a curved front shovel for the Makeblock mBot robot to be used for robot fighting in a sumo arena.
The stock mBot is a great little platform for learning robotics, but its bare front bumper is not built for pushing other robots around a sumo ring. In mini-sumo and similar competitions, the front-end geometry matters as much as raw motor power: a shovel that can slide under an opponent’s chassis, or catch its underside as it turns, is often the difference between winning and being pushed out of the ring. I designed this one with a curved front edge specifically to help it slide underneath a rival robot rather than just slamming into it head-on.
The shovel is provided with protection against sunlight for the infrared sensors, so they can better sense the boundaries of the battlefield. That shroud matters more than it looks: mBot’s line sensors read reflected infrared light to detect the white boundary line of the arena, and under bright competition lighting or sunlight, stray light easily washes out that reading and causes a robot to drive straight out of bounds. Shielding the sensors keeps the robot reacting to the actual ring edge instead of ambient glare.
I also designed a flat front shovel alongside this curved one, since the best shovel shape often depends on your opponents’ style and the specific rules of the competition you are entering. Printing both and testing them against each other is the easiest way to find out which one suits your mBot best.
Both shovels bolt onto the same stock mounting points on the mBot chassis, so switching between them between matches takes a couple of minutes and no permanent modification to the robot itself. If your local competition rules restrict certain shapes or dimensions, it is worth checking those before committing to either version.
Sumo rules and opponent styles vary a lot between events, so it is worth treating both shovel shapes as a starting point to test against rather than assuming one is objectively better than the other for every match.
A cheap kit robot with the right printed attachments can hold its own against far more expensive hardware.
A simple upgrade that turns a kit robot into a real sumo contender.
I would lean toward the curved shovel once you have scouted an opponent’s front end and it looks low or wedge-shaped, since sliding underneath tends to beat a straight head-on push against that kind of shape.
Download
The model is free to download and print, licensed under the Standard Digital File License.