Saloon Sweeper about to compete at UCR's 2025 Spring Fling
Saloon Sweeper will be a Fairyweight horizontal spinner with no wheels, relying entirely on the vibration from its unbalanced weapon and its bristles for movement. It will have only one motor, driving the spinner, one 40-amp ESC, and a 200 milliAmp-hour 2S battery.
Bristle bots use offset spinning weights in order to generate vibration, and "bristles" (in combat robotics, bristles are often taken from toothbrushes or printed out of TPU), to increase the relative coefficient of friction in one direction, and propel the bot forward. "Dynamics of a Vibration-Driven Bristle Bot" by Chandravamsi Gandra was a very helpful resource for deepening my understanding of how bristle bots work, and how to design one.
In combat robotics, bots using nontraditional methods of locomotion are granted a weight bonus, in order to encourage new designs and keep the sport interesting. In the latest version (1.5) of the SPARC Rules, Bristle-drive robots are awarded a 150% bonus, so instead of the Fairyweight class' usual 150 grams, Saloon Sweeper will be able to weigh up to 225 grams.