Vertical flywheels

Vertical flywheels are a type of heavy rotating weapon which first became prominent in later series of Robot Wars. The first robot to be equipped with such a weapon was Daisy Chopper in Series 3, while the most successful UK series competitors to be equipped with one include the Series 7 version of X-Terminator, which finished fourth in that series, Series 5-6 Semi-Finalist S3 and joint Battle of the Stars champion Kadeena Machina. House Robot Matilda was also equipped with a rear-mounted vertical flywheel from Series 5/Extreme 1 onwards, replacing her chainsaw in the UK series and being made interchangeable with it in Robot Wars: Extreme Warriors and Nickelodeon Robot Wars.

Whilst vertical flywheels have not been as common or as famous as their horizontal counterparts in the UK series, robots with this weapon type also enjoyed considerable success in international versions of Robot Wars. Dutch Series 2 Champion PulverizeR and German Series champion Black Hole were both equipped with these flywheels, as was US competitor Cyclone, which won the Annihilator in the second season of Extreme Warriors. They also enjoyed some success in the lower weight categories, with Argh! winning the Extreme 2 Featherweight Championship by using a vertical flywheel to devastating effect.

Definition

 * A  flywheel is a comparatively heavy spinning disc weapon that spins at high speeds. To cause damage, one or more "teeth" are welded onto or integrated into certain places along the disc's circumference in order to gouge and tear large sections off of opponent's armour or destroy vital components.
 * Compared to the horizontal flywheel, these flywheels are mounted vertically, and are intended to strike the bottom edges and sides of other robots.

Advantages and Disadvantages
Advantages
 * Like the horizontal type, vertical flywheels are capable of inflicting substantial amounts of damage to their opponents, tearing into and ripping off sections of armour plating as well as destroying their chassis, wheels and weapons. S3, PulverizeR, 259, Cyclone, Black Hole, Kadeena Machina and Aftershock are among the most prominent examples.
 * Vertical flywheels are capable of doubling as flipping weapons, with most of them being capable of throwing opponents over or even flipping them out of the arena. Matilda, Cyclone, the Series 7 version of X-Terminator and Aftershock all demonstrated this.
 * They often target the underside of a robot, usually considered its weakest point, allowing for maximum damage to its chassis and wheels/tracks. S3 particularly destroyed Plunderbird 5's chassis, armour and wheel mounts during its first ever battle, and Kadeena Machina was able to shred Dee's wheel off.
 * Vertical flywheels also deliver more powerful blows for the same amount of stored kinetic energy as their horizontal counterparts, as robots equipped with them are braced by contact with the arena floor when they hit opponents. This enabled robots such as 259, Kadeena Machina and Aftershock to remain stable even while making repeated attacks on their opponents.
 * They are especially effective against robots equipped with wedges and flippers, effectively neutralising them by buckling the wedge/flipper plate and rendering them unable to negotiate the wielder's ground clearance. X-Terminator demonstrated this in its Series 7 Semi-Final fights against St. Agro and Bulldog Breed.
 * Very rarely, this type of flywheel can also double as a self-righting mechanism, being able to 'kick' robots back onto their wheels if they hit the arena floor or walls and are mounted close enough to the rear of the robot's chassis. Aftershock is the only competitor to demonstrate this capability so far.

Disadvantages
 * Vertical flywheels are often hard to combine with invertible designs, especially larger ones like those used by 259 or Cyclone. This often meant that a robot with this weapon type either required an additional srimech or had to adopt a smaller flywheel. S3, PulverizeR, Black Hole and Kadeena Machina are notable exceptions, all being invertible robots that successfully incorporated powerful vertical flywheels into their designs.
 * Also, the weapon's effectiveness can often be decreased when inverted, due to many flywheels spinning in only one direction. This problem especially affected Black Hole in its European Championship battle against Philipper 2, with its discs spinning towards the ground once the robot was flipped over and causing it to jump upwards upon striking Philipper 2's armour.
 * Vertical flywheels have a narrower attack range than their horizontal counterparts, limiting their precision. Black Hole circumvented this through using two flywheels attached to the same axle, each mounted on either side of the machine.
 * The gyroscopic forces of a vertical flywheel can adversely affect the robot's manoeuvrability, making it difficult for it to turn when the weapon is spinning. Additionally, they could also lift the robot up onto one wheel, or even cause it to overturn when turning left or right. This has happened to Matilda during the first heat of German Robot Wars, Kadeena Machina in the second episode of Battle of the Stars, and Aftershock during its run in Series 9.

List of Robots with Vertical Flywheels
Robots are listed alphabetically. Robots that are not heavyweight are listed with a green background. House robots are listed with a red background.