Killerbee is build around a custom gearbox made from two small hobby servos. Here's a photo that compares the nano sumo gearbox to a pen-racer car.

The exterior of Killerbee are PCBs that also contain the electronics. The PCBs are 0.5 mm thick and single sided. The necessary paint provides the finishing thouch.

The custom connector is a standard 2.54 mm pitch female header connector. It provides the ISP interface, a serial interface and the charging interface. A small SMD switch allows one to switch on/off the bot.

Killerbee has an ATMega8 as its brains. This MCU runs at 16Mhz.

The front object sensor is an is471f from sharp. The IR sources are two surface mount IR LEDs. Both line sensors on the bottom plate are gp2s40. Power to all IR sources can be turned on or off. This is a major power saver, given the very small battery.

The proprioceptive sensor measures the voltage on the battery, by measuring the voltage drop over a constant voltage source - being 3 diodes put in series. Again, power to this voltage source can be turned of for power savings.