Rear-hinged flippers

"In arenas where it's possible to win by throwing an opponent out of the arena, a monster flipper is a viable design choice"

- Aaron Joerger

Rear-hinged flippers are the more common of the two types of flipping weapon seen in Robot Wars. Prior to The Third Wars, most rear-hinged weapons seen in Robot Wars were lifters.

The weapon debuted in the form of Chaos, as the rear-hinged flipping arm. Whilst the arm continued to be used throughout the wars in designs such as Gemini, Hydra and Ewe 2, the more famous design arrived in Series 3 with the arrival of Chaos 2 and Facet. With a wider flipping plate and powerful CO2 reserves, Chaos 2 won consecutive UK Championships and spawned dozens of imitators.

Aside from Chaos 2, a number of famous robots have achieved success with this weapon, including the Series 8 Champion and third-place finisher, Apollo and TR2, and Series 9 runner-up Eruption. Other championship-winning robots with this weapon include Bulldog Breed and Bigger Brother, whilst robots such as Dantomkia, Wheely Big Cheese, Atomic, Thermidor 2 and Gravity have all become famous due to their powerful flippers.

Definition

 * Flippers aim to propel another robot and allow gravity and torque to flip the robot over. This contrasts lifting weapons, which aim to lift, push and tip a robot onto its back or side.
 * A true flipper is defined as a flipper designed to get the entire mechanism underneath its opponent. The surface area of the flipper is much bigger than that of a flipping arm.
 * A flipping arm is typically narrow in width, but extends the same length as a true flipper. It usually features a prong or small wedge on the end to help get under opponents and an extender to provide additional leverage.
 * The weapon is considered rear-hinged because the hinges are at the top of the robot (usually at the top of a wedge or the end of a box-section). When the robot fires its flipper, it gives the impression that a robot is opening its "mouth."

Advantages and Disadvantages
Advantages "Ever since helping Rex to build Recyclopse, I wanted to harness the power of Recyclopse's tongue in a more effective way. By hinging the flipper at the back (instead of the front), you only have to poke a small part of the front blade under your opponent to be able to chuck them"

- George Francis on the weaponry of Chaos and Chaos 2


 * Earlier in the show's run, battles could be ended very quickly by flipping robots over. The largest advantage of rear-hinged flippers is that only a small part of the weapon needs to gain purchase in order to make the crucial attack. Chaos 2 was able to instantly defeat opponents such as Trident and Indefatigable with such attacks.
 * Unlike all other flipping and lifting weapons, rear-hinged flippers rely on gravity to cause damage to the robots. This makes them more dangerous than front-hinged flippers and lifters, which rely on external factors for damage. During the latter part of the series, this became the most viable way for robots to achieve victory, as self-righting mechanisms or invertible designs were almost always present. Apollo was able to immobilise both Kan-Opener and PP3D by launching them with such force that their landings knocked out both robots' removable links. The landing force was also critical in both Apollo and TR2's victories over Carbide, whose weapon stopped working upon impact with the ground.
 * Both variants of rear-hinged flipper can easily double as a self-righting mechanism depending on their design and power. Chaos 2 was the first to do so successfully, in its Series 3 Heat Final against The Big Cheese, and nearly all robots with these weapons were capable of self-righting without the need for a second weapon or srimech.
 * They are possible to fit into an invertible design, as shown by Wheely Big Cheese and St. Agro.
 * As the most powerful of flipping weapons, the rear-hinged flipper is ideally suited to throwing other robots out of the arena. Of the fifteen robots to achieve the feat more than once, only four were not armed with this particular weapon.
 * Gemini was the only robot to demonstrate this using a rear-hinged flipping arm.
 * It is possible for these types of flipper to double as a clamp, increasing the weapon's versatility by allowing it to grab hold of opponents positioned in the space between the flipper and the robot's body. This was the reasoning behind the weapon designs for Eric, Reactor and Constrictor, and has been successfully demonstrated by Bigger Brother, The Grim Reaper, Apollo and Rapid in combat.
 * Rear-hinged flippers, like lifters, could offer a useful weapons synergy with overhead axes or hammers. Comengetorix and Hydra were a handful of robots to pair flipping arms alongside their overhead weapons, while Axe-Awe and later versions of Iron-Awe combined their axes with a larger front flipper.

Disadvantages
 * As with all other pneumatic weapons, CO2-powered flippers only have a limited supply and amount of flips before running out of gas. Having unsuccessfully flipped Tough as Nails around the arena in its Series 7 Heat Final, Robochicken's flipper lacked the power to throw it out of the arena when it was finally in a position to do so.
 * Compared to other types of flipping weapons, rear-hinged true flippers are the least effective for self-righting due to the increased amount of leverage required. Furthermore, their limited gas supply also prevents them from self-righting when the supply runs out. Robots such as Chaos 2, Thermidor 2, Tsunami and TR2 all notably succumbed to defeat once they became low on CO2, and were unable to use their flippers to self-right after a certain amount of flips.
 * Flipping arms can be even less capable as self-righting mechanisms, depending on the robot's design. Due to various issues with the design of the robot or their arms, Chaos and the Series 6/Extreme 2 version of Hydra were all unable to self-right after being flipped over.
 * Flipping plates are often fragile and vulnerable to being damaged by axes, hammers, crushers, or heavy rotating weapons. Chaos 2's flipper sustained damage from robots like Razer, Dominator 2 and 13 Black, whilst Bigger Brother's weapon was completely destroyed during its battle with Hypno-Disc.
 * Rear-hinged flipping arms are especially susceptible to breaking off after a few flips or being damaged by spinning or crushing weapons. Both Comengetorix and Oblark suffered from this issue in at least one of their battles.
 * Flippers without sufficient knock-out power became less damaging when self-righting mechanisms and invertible robots became more popular.
 * If an opponent gets underneath a flipper's ground clearance, the flipper-wielding robot is instantly set at a disadvantage as the lower end of the flipper is no longer able to reach the ground to achieve any flips. Tornado and Storm 2 had particularly low ground clearances that were able to defeat opponents such as Chaos 2, The Grim Reaper, Gravity and Eruption in this way.
 * Being narrower, rear-hinged flipping arms are harder to get underneath an opponent than full-sized flippers, often missing their targets and requiring skilful driving to flip them over. George Francis particularly cited these weaknesses as being detrimental to Chaos' performance in Series 2.
 * When the flipper is opened, the robot's internals could be left vulnerable to front-on attacks from spike, spear, crushing or spinning weapons. This was best shown in Stealth's Series 3 battle against Hypno-Disc, where Hypno-Disc destroyed the pneumatic rams powering Stealth's flipper when the weapon was fully raised.
 * If the robot's wedge or the lower lip of its flipper is damaged, the robot's ability to negotiate an opponent's ground clearance is instantly diminished, rendering the wedge and/or flipper completely ineffective. St. Agro's and Bulldog Breed's losses to X-Terminator were due in no small part to their flippers getting buckled by the latter's flywheel.
 * If a robot is stranded on its rear, gravity can keep a flipper open and prevent it from self-righting. This has been demonstrated by Ripper in Series 7, and TR2 in Series 8.
 * Heavy rotating weapons can twist a flipping plate so that it no longer sits in place, rendering it almost useless for breaching ground clearance. Both Apollo and Eruption required extensive repairs after taking heavy hits from Carbide and Ironside3 respectively.

List of Robots with Rear-Hinged Flippers
Robots are listed alphabetically. Robots which are not heavyweight entries are listed with a green background. House Robots are listed with a red background.