A few of the minisumo's that I have built

Minisumo Solo, Machined out of a solid 3/4 inch steel plate. The wheels are just under 1 inch in diameter making this one of the lowest profile minisumo's out there. It moves a bit slow for my liking (about 19in/sec)

Has a custom designed PCB just over one inch in length and three inches in width. Onboard is everything needed to run the minisumo including 20V 5A motor drivers designed from low voltage hexfets. The brain is an TQFP ATMEGA8 running at 1Mhz.

Uses 150mAH Li-poly cells, good enough to keep it running for half an hour or so.

The body for my next minisumo Rhino.

As you can see it's about half wheel.

Should be able to go about 60in per second (waaay to fast to control) when it's done. Of course I will PWM to slow the motors down but if I happen to align the opponent in front.... Ergo Rhino!

I can already tell that the front will pop up when it accelerates but the steel front edge it will have will help a bit.

My second competitive minisumo "S.S. Raptor". Smaller, sleeker and faster than it's predecessor but unfortunately doomed from the start. During It's initial test it worked beautifully for about 10 seconds before the gear train stripped out of the motor.

Built this one in about three days but completely lost interest in finishing it after I found out how weak the motors were.

Uses basically the same control as Ender's Wraith.

Some stats:

- ATMEGA8 programmed with Winavr
- L293D motor Driver
- Custom molded polyurethane tires
- 850mAH Li-poly batteries
- Stainless steel shell
- Horribly inadequate motors

Back

My first competition class minisumo "Ender's Wraith" Built in two days for something to compete with in the San Francisco Robolympics competition

The new polyurethane tires were made after the competition, it can now go full speed without overshooting the edge. Full speed it crosses the minisumo ring in just over a second.

The motors are Escaps 33:1 planetary gearing and are way overpowered, not that that's a bad thing but they take up so much room.

The bottom plate is 18ga satin coat steel bought sometime in the 70's used to line the walls of an old quonset, now it's the base of my minisumo!

The body material is mostly UHMW (ultra high molecular weight plastic) It's fairly slippery stuff similar to Teflon, leftover scrap from the lining of a machine.

4 sharp GP2D12 IR rangers for opponent detecting, just a pair of QRD1114 sensors on the bottom for line detection.

Uses 3 * 850 mAH lithium polymer batteries running the sumo at 11.1V. The Ni-Cads I originally tried just didn't last long enough.

Watch Enders Wraith go up against Returner in a grudge match on the movies page (Returner actually won first place at Robolympics)

Has won Second place at 2004 Robolympics, First place at 2004 WCRG, Second place at PDXbot and First place at Robothon and first place at ECRG.