Pseudo Sumo in that it doesn't quite fit within the 100mm x 100mm limit of the Mini Sumo rules. It's just a design to allow functionality programming and testing of the sensors and components.
It's inspired by Push-E: http://www.thingiverse.com/thing:1724693 with a simpler way to connect batteries.
It uses the cheap yellow plastic gear motors that are around everywhere.
The battery box has been recently added and not tested. I've used a bought four battery enclosed holder on the prototype and have not yet fitted the printed version.
The Arduino sketch is still a work in progress but I'll upload it once all the basic functions are complete.
I've used two IR line following sensors to ensure it stays within the dohyo and two digital IR sensors for tracking the opponent. It would make sense to replace these with analogue ones so the tracking and hunting algorithms can be refined.
The holes are tight on the models as I use screws not bolts to hold everything together - the screw thread just bites into the PLA. Nuts and Bolts would be preferable on an actual fighting sumo as the mechanical hold would be better.