Plastic armour

Plastic Armour
Killerhurtz, armoured in transparent polycarbonate
Example Materials	Polycarbonate, HDPE, Perspex, Polypropylene
Robots
Pioneer(s)	Andy Roid (1994 US competition) Killertron (televised series)
Notable Robots	Panic Attack, Chaos 2, Tornado, Terrorhurtz, Carbide, Gabriel

Plastic armour was a very common armour type used throughout all versions of Robot Wars. Armour of this description consists of various non-metallic materials made from of synthetic polymers, including polycarbonate, polyethylene and polypropylene.

Various competitors from the 1994-1997 US competitions were armoured with plastics of differing types. Among the first documented to use these materials in this way was 1994-1995 lightweight entrant Andy Roid, which was built out of a Big Wheel children's tricycle. A number of robots from this era were also among the first to adopt custom armour and chassis components made out of plastic materials, including polycarbonate. 1996-1997 heavyweight Gutrip and the featherweight Spike were two such examples, both utilising polycarbonate in the form of Lexan sheets.

In televised series, plastic armour first appeared in Series 1 on various competitors, including Killertron (repurposed wheelie bin lid) and Bugs (repurposed vacuum cleaner). By Series 2, custom-fabricated sheets and chassis components made from plastics began to become more popular, as seen on competing robots such as Cassius, Griffon and Killerhurtz.

As the second-most common armour type after metal, plastic armour enjoyed plenty of success by robots utilising it throughout the course of the show's history. UK Grand Champions Panic Attack, Chaos 2, Tornado and Carbide are amongst those to use various types of plastic in each of their championship-winning runs.

Definition

Plastic armour is an umbrella term for many different types of armour sheets made from synthetic polymers.

Polycarbonate (Polycarb)

King B Powerworks shows off its transparent polycarbonate armour

Polycarbonate is a polymer which contains the signature carbonate group (−O−(C=O)−O−). Usually commercially available, it was primarily used for robot building as sheets which can be cut or moulded in similar ways to sheet metals. Team Hurtz machines took this one step further, using this material for chassis bulkheads and baseplates along with top, side and rear panels. An advantage that polycarbonate has is that it can flex and bend freely without cracking or breaking, unlike other similar thermoplastic materials. Its high impact resistance also enabled it to be used for the inner and outer walls of the Robot Wars Arena, often being referred to in this application as bulletproof glass.

Polycarbonate can come in many different colours, including transparent sheets, which robots such as King B Powerworks and the Team Hurtz machines utilised for aesthetic reasons. The brand names Perspex, Makrolon (often misspelt as Macrolon) and Lexan have often been used interchangeably when describing this material, the latter being especially commonplace in North America.

Polyethylene and HDPE (High Density Polyethylene)

Gabriel 2's HDPE wheel bends, before elastically reforming into its original shape following a hit from Carbide's spinner

Polyethylene is a polymer made up of the (C₂H₄)_n group and is a common material in industrial applications. Not only is it a high-strength material compared to other armours, but it has high ductility and impact strength, meaning it can absorb forceful and high-speed impacts effectively.

High Density Polyethylene (HDPE) is a denser, corrosion-resistant variant of the material with increased strength and impact resistance, commonly used to manufacturer pipes. First used by Series 2 competitor Rameses II, it would later see much greater usage in the Revival Series due to its high plastic deformation yield point. Notable robots made out of HDPE include Gabriel, which utilised the material for its chassis, wheels and a number of its interchangeable weapon arms.

Polypropylene (Polyprop)

Agent Orange, using the weight-saving polypropylene armour

Polypropylene is a polymer made up of propene (CH₃CH=CH₂) chains. It has a lower density than the other common plastics used as armour in Robot Wars, making it a good choice for teams trying to save weight for their armour, while still offering reasonable durability. Team Panda cited the material's durability in using of it for their debut entry Panda Monium, which proved particularly resilient against smaller rotating weapons such as chainsaws. Series 3 competitor Agent Orange also specifically used polypropylene due to its lightness over other materials.

Other Plastics

The plastic body of Hippobotamus is played for design over protection

Plastic in general is an easily reusable material that can be taken from unlikely sources and repurposed into robot armour. Examples of this include the vacuum cleaner of Bugs and the painted wheelie bin lid of Killertron, both utilising pre-existing objects made from this kind of material. However, in other cases, a team can use a pre-made plastic material as a deliberate aesthetic choice. None is more obvious than Hippobotamus, a bright yellow plastic sandpit resembling a hippopotamus.

Advantages and Disadvantages

Advantages

• Despite the name, most plastics selected as robot armour have a high elastic deformation limit, allowing them to bend and return to their normal shape following impacts from weapons. This makes them especially effective at absorbing attacks from high-powered spinners and overhead weapons.
  • The latter condition means that plastics can sometimes be used in conjunction with other materials to deflect certain attacks. In Series 10, Heat C, Vulture and Rapid added defences incorporating plastic panels to absorb blows from Terrorhurtz's powerful axe.
• Plastic is often lighter than metals of a similar thickness, thus giving the robot more weight to use for other aspects of its design including weapons and drive systems.
• Plastics can be coloured and moulded in production, allowing for a large range of aesthetic choices for the robot.
• Plastic armour can be salvaged from scrap or repurposed for very little cost. Certain types can also be recycled (e.g. HDPE, polycarbonate, polypropylene) or made from recyclable material, offering potential environmental benefits concerning the reprocessing and reuse of these materials.

Disadvantages

• Whereas some metals can be welded and fixed easily, plastic materials often have to be precision-moulded (e.g. those used for 3D-printed components), or attached with screws or glues. This makes the panels easier to rip off compared to metal equivalents, especially plastic sheets which are externally mounted.
• Plastics have a lower melting point than many other armour materials, so can melt under prolonged and intense heat. This can not only compromise the robot's structural integrity, but also pose risks for a given robot's internals, which may sustain heat or fire damage as a direct result.
• Plastics may have a high impact resistance, but they lack the strength of metals, so can often buckle under constant pressure.
• Though generally impact-resistant, polycarbonate plastics are more susceptible to getting punctured or torn open, depending on the thickness and the power of the weapons attacking them.
• Transparent plastics make it easier for opposing teams to work out where critical components are during a battle, thus potentially allowing them to aim for these to damage or immobilise a certain robot.

List of Robots with Plastic Armour

Due to plastics being a significantly popular armour material, a selection of notable or recognisable users of each major variety of plastic has been listed below.

DESKTOP MODE ONLY: Robots which are not heavyweight entries are listed with a green background. Robots from the 1994-1997 US competitions are listed with a purple background.

Polycarbonate

Robot	Series Appearances with Polycarbonate armour	Details	Notes	Image
13 Black	Series 6	Polycarbonate covered body and wheelguards.	One of only three unseeded Semi-Finalists in Series 6.
Anarchy	Series 6	12mm transparent polycarbonate sides, simultaneously protecting and revealing the robot’s walking mechanism.	Used in tandem with a 6086 T6 aluminium chassis and armour. Most successful walking robot, reaching the Heat Final in its only appearance.
Carbide	Series 9-10	12mm 'bulletproof glass' top armour; acknowledged as polycarbonate in statistics for Series 10. Used in tandem with a 'military-grade' steel and aluminium construction.	Series 9 Champion; also finished runner-up in Series 10 with this armour configuration. Also utilised shock-mounted plastic top armour of an undetermined type in Series 8.
Cassius	Series 2, 3	Painted polycarbonate panels in Series 2; transparent sheets in Series 3 (Cassius 2).	Series 2 runner-up.
Chaos	Series 2	Clear polycarbonate panels.	First televised robot acknowledged as using transparent polycarbonate armour.
Chaos 2	Series 3-6, Extreme 1-2	Black polycarbonate front and flipper covers; clear polycarbonate rear panel.	Series 3 and 4 UK Champion; used in tandem with Dural alloy and titanium plating.
Fluffy	Series 5-7, Extreme 1-2	16mm polycarbonate.
Griffon	Series 2-3	Another polycarbonate pioneer from Series 2; clear panels with 5mm thickness.	Winner of the Series 2 Internet Insurrection.
Gutrip	1996-1997 US Championships	Transparent Lexan shell with sloped sides.	1996 Heavyweight Face-Off Quarter-Finalist and Heavyweight Melee Finalist.
Killerhurtz	Series 2-4	All-polycarbonate chassis and armour; often referred to as Lexan by John Reid.	Transparent armour, later adopted as a signature visual style for Team Hurtz machines.
M2	Series 7	Polycarbonate top panels, metal chassis and side panels.	Series 7 Semi-Finalist, despite the armour being easily pierced by Tiberius 3.
Panic Attack	Series 2, 4-5, 7, Extreme 1-2	Multiple versions used polycarbonate as a sandwich sheet with bulletproof fibreglass and aluminium.	Series 2 champion.
Prizephita	Series 4-5	"Transparent bulletproof polycarbonate".	Series 4 and 5 incarnations only; the latter reaching the Heat Final as Prizephita Mach 2.
Spike (1996-1997)	1996-1997 US Championships	Lexan panels. The original 1996 incarnation featured a large wedge-shaped shell with a semi-transparent appearance.	Featherweight Face-Off Semi-Finalist in both years, also a Featherweight Melee Finalist in 1997.
Terrorhurtz	Series 5-10, Extreme 2	Predominantly polycarbonate and steel construction. Thickness of up to 12mm for the main chassis bulkheads in later incarnations. Only robot to use clear polycarbonate throughout the complete Revival Series.	Fourth place in Series 6.
Tornado	Series 4-7, Extreme 1-2, US Season 2	6mm TUFFAK polycarbonate, partially laminated in titanium for Series 5 and Extreme 1. Variable thicknesses adopted from Series 6 onwards to accommodate different interchangeable weapon configurations.	Series 6 Champion; also finished third in Series 7 and reached the Semi-Finals on its Series 4 debut. Run of 32 victories in the UK Series.
Vector of Armageddon	Series 1	Used Lexan sheets.	Featherweight.

Polyethylene

This list details robots using regular Polyethylene armour, as well as High Density Polyethylene (HDPE). Robots which are not heavyweight entries are listed with a green background.

Robot	Series Appearances with Polyethylene armour	Details	Notes	Image
Barber-Ous	Series 5-7, Extreme 2	Polyethylene full-body drum painted to resemble a barber's pole.	"The strengths; it's made of plastic, the weaknesses... oh, it's made of plastic. Curious." — Jonathan Pearce on Barber-Ous 2's statistics Series 6 Heat Finalist as Barber-Ous 2.
Broadsword	Extreme 2	HDPE pipe.	Middleweight.
Constrictor	Series 7	10mm Grade 500 HDPE.	Combined with 3mm aluminium.
Gabriel	Series 8, 10	HDPE wheels and body; maximum thickness quoted in Series 8 as 25mm, and in Series 10 as 15-20mm. Used in tandem with 6.2/6mm hardened steel plating.	Made predominantly out of HDPE, Gabriel's large and flexible wheels absorbed repeated impacts from powerful weapons without taking too much damage themselves. Series 8 Heat Finalist; wheels crucial to a famous Group Battle performance against Carbide as Gabriel 2.
Jellyfish	Series 9	HDPE construction, officially quoted as varying in thickness between 20-100mm.	Design incorporated plenty of plastic googly eyes.
Nuts	Series 8-10	HDPE wheels and top/base armour for the main robot; used in tandem with a HARDOX chassis and mild steel ring.	Each of the minibots was armoured with 8mm HDPE, later upgraded to 10mm HDPE.
Rameses II	Series 2	HDPE bodyshell.	Pioneer of HDPE armour in Robot Wars; chosen to specifically counter cutting attacks from chainsaws.
Rapid	Series 10	20mm HDPE.	Large shock-mounted panel added to the top of the rear-hinged flipper, used as extra defence in its Heat Final against Terrorhurtz. This modification allowed Rapid to survive and win to reach the Grand Final of this series.
Sabretooth	Series 8, 10	Two layers of HDPE for the Series 8 chassis; Series 10 version also used layered HDPE alongside 3.2mm HARDOX.
Tauron Mk 2	Series 10	10mm HDPE top and bottom panels, used in conjunction with 4mm HARDOX.	Replaced the 6mm polycarbonate of the original Series 9 incarnation; used in place of polycarbonate for added flexibility during impacts.
THE BASH	Series 10	HDPE.	World Series only. Homage to the House Robot Sgt. Bash; used in tandem with hardened and regular steels.
TMHWK	Series 9-10	5mm HDPE side panels.	Used in tandem with 3.2mm HARDOX.
Wyrm	Series 9	Ultra-high molecular weight polyethylene (UHMWPE) frame.	Used in tandem with polycarbonate and a front HARDOX lifting wedge.

Polypropylene

Robot	Series Appearances with Polypropylene armour	Details	Notes	Image
Agent Orange	Series 3	Polypropylene	Chosen due to its lightweight properties.
Nasty Humphrey	Extreme 2	10mm Polypropylene sheets.	Combined with 6mm aluminium.
Panda Monium	Series 2	Expanding foam polypropylene panels; chosen by Team Panda for its 'very, very impact resistant' properties.	Fixed to the robot’s steel chassis with aluminium strips; proved resilient against Matilda’s chainsaw in the Skittles Trial.
T-Bone	Series 5	Polypropylene gas pipeline.
Tiberius	Series 4-5	Polypropylene.	Also used Lexan polycarbonate, nylon and steel.

Other or Undetermined Plastics

This section is for other rarely-used plastic materials which were used as armour throughout the televised show and 1994-1997 US events.

Robot	Series Appearances with Plastic armour	Material	Notes	Image
Andy Roid	1994-1995 US Championships	Plastic "Big Wheel" children's tricycle.	1994 Lightweight Face-Off runner-up.
Androne 4000	Series 10	6mm "Wear Plastic".
Bugs	Series 1	Plastic vacuum cleaner.	Featherweight pioneer of plastic armour.
Crushtacean	Series 9	Polyurethane paint.	A "tough and durable" protective layer designed to resist spinning weapons.
Direct Action	Extreme 2	Nylon.	6mm sheets.
Hippobotamus	Extreme 1, Series 5	Plastic sandpit.
Killertron	Series 1-2, 4, Extreme 1	Repurposed wheelie bin lid.	Fourth place in Series 2.
King Buxton	Series 4-5, 7-8, Extreme 1	Perspex (also referred to simply as polycarbonate) panels.	Transparent to show the internals. The Series 8 incarnation King B Remix incorporated 16mm polycarbonate and 16mm UHMWPE.
Razzler	Extreme 1	Plastic toy.	Antweight; a converted radio-control version of the official Razer Pullback toy.
Splinter	Series 4	Plastic oil drum.	Used to form the robot's front scoop; Series 4 Semi-Finalist.
The Creature	Series 4	Polystyrene.	Light, mouldable material for the robot's decorative outer shell.
The Predator	Series 4	Teflon.	Aluminium-covered Teflon sheets.