---
title: "Robot combat"
chunk: 4/11
source: "https://en.wikipedia.org/wiki/Robot_combat"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:20:55.912995+00:00"
instance: "kb-cron"
---

Vertical Spinner – A vertical disc or bar spinner consists of a thick circular disc or flat bar mounted on a horizontal axis. Rather than many small teeth to cut like a saw, most spinners have few large teeth to catch opponents and either throw them into the air or rip off chunks of armour. Vertical spinners are ubiquitous at all levels of competition, especially in the US. A majority of BattleBots competitors use spinning vertical discs or bars, and it is the most successful weapon type in the show. Notable robots using vertical spinners include 1.0 lightweight champion Backlash, its heavyweight brother Nightmare, 2018 and 2019 champion Bite Force, and 2021 champion End Game, among many others. 2022 BattleBots champion Tantrum bears a "puncher", with a small vertical spinner mounted on a sliding mechanism. Vertical spinners are less common in Robot Wars, with Series 5–6 competitor S3, Series 7 grand-finalist X-Terminator, and Series 9–10 competitor Aftershock as three notable exceptions.
Drum Spinner – Drum spinners are a variant of vertical spinners, consisting of a thick, short cylinder resembling a steamroller's wheel with teeth spinning on a horizontal axis. Drum spinners can accelerate faster than vertical discs or bars, but have less reach. Good drum spinners can land a solid hit almost every time they contact another robot and send it flying as high as a normal vertical disc or bar. Drums are also much thicker, meaning almost the entire front of the robot is taken up by a weapon. Drum spinners tend to suffer from extreme drive issues due to the large amounts of gyroscopic forces. Among the most successful drum spinners are designed by the Brazilian Team RioBotz: BattleBots competitor Minotaur and its RoboGames equivalent, Touro Maximus. Four-wheeled drum spinners are a popular design in China, with RoboGames competitor Chiyung Jinlun and King of Bots competitor Xiake (from the same team) as reliable finalists in televised competitions. Drum spinners are also effective at lower weight classes, such as two-time RoboGames lightweight champion UnMakerBot, NHRL champion beetleweight Shreddit Bro, and the commercially available Weta kit beetleweight bots.
Eggbeater – An eggbeater spinner is similar to a drum but uses a broad rectangular frame, rather than a solid cylinder as its choice of weapon shape. Eggbeaters are lighter and have a higher moment of inertia (and thus higher rotational kinetic energy) per unit of mass than drums, but due to their less aerodynamic design, they are usually most effective at lower weight classes. The 3-pound (Beetleweight) robot Lynx has dominated its weight class to such an extent that it temporarily retired to give other teams a chance to win. Robots in heavier weight classes have started to adopt eggbeaters despite high fabrication costs, with Riptide reaching the quarterfinals in its 2022 BattleBots debut and the following season.
Vertical discs, bars, drums, and eggbeaters are continuous with each other to the point where it can be difficult to cleanly define each weapon type. For example, BattleBots 2019 and 2022 runner-up Witch Doctor has used a two-toothed "drisc", which is narrower than a drum but broader than a disc. BattleBots competitor Copperhead uses a broad steel drum with notches cut out, giving it similar properties to an eggbeater. Brazilian Team Ua!rrior has fielded successful drisc and eggbeater bots at multiple weight classes, including Federal M.T. (four-time RoboGames lightweight champion), General (two-time RoboGames middleweight champion), and Black Dragon (2019–present BattleBots competitor)