- "Sweeney Todd is the only Robot Wars competitor to use Mecanum wheels - a conventional wheel with a series of rollers attached to its circumference. This means it can move in every direction, not just forwards and backwards."
- — Robot Wars: Build Your Own Robot
Sweeney Todd was an invertible robot which competed in Series 8 of Robot Wars. It was built by an Oxford-based team, and was notable for being the first competitor to feature Mecanum wheels as a method of locomotion. However, it lost its Group Battle after becoming immobilised following attacks from PP3D and Apollo.
Sweeney Todd was constructed from 4mm of thick steel, and is armed with a circular saw, which according to the official Robot Wars website, was powerful enough to cut through steel and concrete. Sweeney Todd was the first robot in the history of Robot Wars to use Mecanum wheels, which have rollers attached to allow the robot to drive in any direction without turning. This gave Sweeney Todd high manoeuvrability, although it would still need to turn manually in order to point its circular saw at opponents.
Sweeney Todd weighed a mere 45kg, notably 10kg lighter than the maximum weight for middleweight robots. With the heaviest competitors in Series 8 weighing 110kg, Sweeney Todd was under half the weight of most competitors.
The name Sweeney Todd was derived from the antagonist of the 1846-1847 story series, The String of Pearls. Stage productions and films named after Sweeney Todd would later be produced, based on the same character.
- "This is the first attempt that anyone on this team has made at building a fighting robot. The team say they have had plenty of experience in building robots for other applications, such as autonomous hovercrafts and test rover bots, in their jobs as engineers, and so wanted to try out building a fighting robot too."
- — The official Robot Wars website
Sweeney Todd was entered by a team of engineers from Oxford. The Team Captain was Sean Cleary, an electronics engineer, along with software engineer Laurence de Bruxelles and mechanical engineers Jon Elmer and Dominique Andreson.
Sweeney Todd appeared in Heat 4, where in the first round, it faced former Annihilator champions Kan-Opener, full-pressure flipper Apollo, and undercutting spinner PP3D, built by Gary Cairns from the team that won Series 7 with Typhoon 2.
- "I can't wait to see you guys waltzing around the arena!"
- — Angela Scanlon references Sweeney Todd's unique locomotion
Its role at the start of the battle was passive, avoiding the other robots, only bringing its angle grinders into play onto Apollo when it had lost drive on one wheel. Sweeney Todd returned to the background, avoiding danger until PP3D attacked it, ripping an angle grinder out of Sweeney Todd. It became clear that Sweeney Todd was immobilised by this attack, only showing movement by coasting. It sustained more damage from PP3D, warping the shape of its body, and was flipped into the arena wall by Apollo. As Sweeney Todd was finally counted out, it was hit by PP3D, and was somersaulted by Apollo, and sent spinning away by the final blow from PP3D. It was eliminated from the competition, alongside Kan-Opener.
- "It was a bit disappointing, but you know, we came here for fun!"
- — Dominique Andreson
|SWEENEY TODD - RESULTS|
|Series 8 - UK Championship|
|Heat 4, Group Battle||vs. Apollo, Kan-Opener, PP3D||Eliminated|
- Wins: 0
- Losses: 1
|Series||Sweeney Todd Series Record|
|Series 1-7||Did not enter|
|Series 8||Heat, Round 1|
|Series 9||Did not enter|
|Series 10||Did not enter|
- Before building Sweeney Todd, the team had experience building autonomous hovercrafts and test rover bots.
- Sweeney Todd was one of only four robots in Series 8 to not use modern lithium polymer or nickel metal hydride batteries inside the machine, the others being DisConstructor, Kill-E-Crank-E and The General, which also used lead acid batteries.
- In October 2016, Dominique from the team won the 'Best Female Role Model on Robot Wars' award at the 2016 IET Engineering the Future Festival, an award created by judge Noel Sharkey.
- In Series 6, Jonathan Pearce referred to Barber-Ous 2 as "the Robot Wars Sweeney Todd".
- Sweeney Todd was the only robot from Heat 4 of Series 8 not to appear in another episode besides said episode.
- At 45kgs, Sweeney Todd was the lightest robot to enter Series 8.
- Sweeney Todd was the second middleweight to fight in a heavyweight Championship. The other was Marauder in Extreme Warriors Season 2. Both Thor's Hammer and The Piecemaker fought heavyweights in an Annihilator.