- "What is a removable link? Well, to start with it's the main safety feature required on every robot that enters the Robot Wars arena. It's a plug that goes directly in line with the batteries of the robot, which when taken out removes all power from the machine. Without this link in place it's impossible to drive the robot or activate its weapons accidentally."
- — Robot Wars: Build Your Own Robot[1]
Removable links (often just called links and sometimes referred to as safety links, power links, keys or killswitches) are small detachable power switches which are used to activate and deactivate all robots participating in Robot Wars and other robot combat events, including House Robots.
Once removed, a removable link automatically cuts off power to the robot's drivetrain and weapons. This renders the machine immobile, making it safe for transportation, inspection and maintenance in The Pits. It was not uncommon for them to either come loose or fall out completely midway through a battle, if a robot was hit in the area where the link was housed. In turn, this would instantly immobilise the affected robot; notable cases include Bulldog Breed 3's loss to Hypno-Disc in Series 5 and Apollo's loss to Carbide in the Head-to-Head rounds of the Series 8 Grand Final.
The term failsafe - referring to a completely different component - was frequently conflated with link even on Robot Wars itself, leading to occasional confusion. While both serve to make robots safe for handling by roboteers and other personnel, the most important difference is that while a failsafe cuts off power to a robot when it loses radio signal from its transmitter, a link cuts off power entirely upon being disconnected from the robot's systems.
Design[]
- "A safety link that every robot has, so it can be immobilised, in The Pits, for security reasons. Pull that out, and the machine will stop."
- — Jonathan Pearce summarises the purpose of a removable link, following Bulldog Breed 3's immobilisation against Hypno-Disc in Series 5, Heat B
Peter Redmond with the link ejected from Diotoir in World Series, Episode 1
Bulldog Breed 3's removable link (left) after getting ripped out during its Series 5 Heat Final against Hypno-Disc
Removable links are roughly rectangular-shaped with power sockets at one end and a wire forming a solid hoop-like extension on the other; the latter feature gives the device a close resemblance to a padlock. They can either be custom-designed or made out of commercially-available power connectors, such as Anderson connectors. The very compact design of removable links allows them to be easily attached to or detached from the robot's electrical system.
CAD model of the Series 9 Pulsar; the dual drive/weapon links are circled in red
Although most robots only required a single removable link, it is not uncommon for robots - especially in the rebooted series - to have two or more independent links for the drive and weapon systems. Additionally, duplicate links are required in order to allow invertible robots to be disabled from the inverted position (see Rules). For Series 8-10, the link was also required to demonstrate that the mandatory LED power light turned off whenever it was disconnected from the robot, confirming its deactivation.[2]
Rules[]
After Behemoth became unresponsive to radio signals and stuck in forward drive in its Series 7 battle against Mute, the removal of its link allowed it to be safely extracted from the arena. The circumstances in which Behemoth lost radio reception - Mute touching its aerial and causing the radio interface to crash - prevented the robot's failsafe from cutting off its power supply.
Removable links or keys became a required safety device from Series 4 onwards,[3] but in series prior to that the robot's main power switch could take any form. Some pre-Series 4 competitors - such as Disruptor - did not even feature a power switch or removable link at all.[4]
By contrast, the design of Mortis incorporated a removable link for safety from as early as Series 1, and it was Random Violence Technologies' implementation of the device that compelled Senior Technical Consultant Derek Foxwell to encourage its wider use.[5] Isolator switches with removable keys or pins were also a popular option among competitors in earlier series, both devices providing similar functionality to links. Examples of robots featuring these included the Series 2 incarnations of Dreadnaut and Killertron, which both lost Arena battles due to the key or pin falling out, or being dislodged by another robot.
From Series 5 onwards, the rules were clarified to only allow links as the main cut-off switch.[6] Sometimes, however, links still continue to be referred to as 'keys' by roboteers, such as Pete Collier following Hot Pants' loss in Series 6.
Removable links are required to be positioned in a visible part of the robot's bodywork, accessible to members of the Robot Wars technical crew from behind the arena wall. They must also be clearly marked, kept away from any moving components such as weapons and drive systems, and able to be removed even while the robot is inverted. Most robots - especially in the original series - would have links concealed behind a hinged cover within their armour, which roboteers were required to be able to open without the use of tools.
For the rebooted series, additional rules were introduced regarding links on invertible robots; in the Series 8, 9 and 10 build rules, robots built this way were required to have a duplicate link 'fitted in the opposite panel' which could be accessible from the inverted position.[7][8][9]
References[]
- ↑ Robot Wars: Build Your Own Robot, p.40.
- ↑ ibid, p.42.
- ↑ Series 4 Build Rules
- ↑ 'disrupt', Oliver Steeples website entry on Disruptor (archived)
- ↑ Arthur Chilcott's comment in the Unofficial Robot Wars Facebook group
- ↑ Series 5 Build Rules
- ↑ Series 8 Build Rules
- ↑ Series 9 Build Rules
- ↑ Series 10 Build Rules