Hobgoblin

Hobgoblin
Participation Information
UK Series	9-10
Team Information
Team	Team Hobgoblin
Team Members	Harry Hills Paul Hills (Series 9) Matt Smith (Series 10) Andy Russell (Series 10)
From	Reigate, Surrey
Associated Robots	Sabretooth (Harry Hills)
Robot Statistics
Weight	110kg
Top Speed	12mph
Power	8s LiPo battery (29.6v)
Drive	500w brushed DC motors
Weapons	Egg beater spinner
Statistics correct as of its most recent show/competition appearance, or if not applicable, qualification attempt.

"Don't panic, and try not to die!"

— Advice in robotics from Harry Hills

Hobgoblin was a heavyweight robot which competed in Series 9 and 10 of Robot Wars. At a cost of £1400, it was built by Harry Hills, who competed in Series 8 as part of Team Legion, although drive problems and a lack of a self-righting mechanism led to Hobgoblin falling in the first round of Series 9, while faulty batteries hindered it in both of its Series 10 losses.

Design

"Hobgoblin is the only 'egg beater' spinner ever to have entered the competition. It's a 20kg vertical spinner that spins at approximately 2,500rpm and has a diameter of 250mm, creating a tip speed of 80mph."

— Robot Wars: Build Your Own Robot on Hobgoblin in Series 9

Hobgoblin in Series 9

Hobgoblin's weapon is referred to as an ‘egg beater’, a popular weapon in lower weight classes, but was the first of its kind to be seen on Robot Wars, and is a rarity for heavyweight robots in general. The beater weighed 20kg with a spinning speed of 2500rpm, and was made from a plasmacut block of HARDOX 500. Rectangular-shaped with two teeth on one side and one longer tooth on the other, the beater had a diameter of 250mm, and was driven by a 24V, 4kW Lynch 170 motor to deliver a tip speed of 80mph in Series 9, and 90mph in Series 10. Hobgoblin was four-wheel driven, and its 5-inch wheels were custom-made from plastic billet, wrapped in cut-down bike tyre for extra traction. In Series 9, both the weapon and drive system are powered by 4x 6s (22.2v) Lithium Polymer batteries.

"Onto the last big machining job for gob. The huge timing pulley used on the first version was just a bit too huge and fragile to be much use. Also the beater was geared very conservatively. Spin up was gutsy and instant but it was just far too damn slow. To solve this a toothless, smooth aluminium pulley was called for. The smooth surface would act as a kind of ghettoclutch which would let the belt slip on huge impacts and save the weapon motor. I also reduced the weapon gearing from 2:1 to 1.5ish:1 which brought the beater into the 3k range theoretically."

— Harry Makes Things blog on the improved spinner

Hobgoblin's internals

Originally, Hobgoblin was built on a budget of £1400. Hobgoblin's frame was made from 4-8mm HARDOX and water-cut high-grade aluminium; 30, 25 and 20mm. The outer shell was mostly made from watercut HARDOX, and for Series 10, 1 inch thick sheet of HDPE was added to the sides. In Series 9, it ran on 24V, 500W lawnmower motors for a top speed of 9mph, but these were replaced with brushed DC motors in Series 10 for a top speed of 12mph, and the batteries were improved to more powerful 29.6v Drive 8s Lipos.

"The drive was going from a single ESC to two, allowing a greater current handling ability and therefore less “why does my robot not move” syndrome"

— Harry Makes Things blog on the change of drive

Hobgoblin in Series 10

At the time of Series 9, Hobgoblin featured a front wedge, designed to lead robots into the egg beater, which was made from a single sheet of HARDOX. However, this wedge was replaced with a toothed face Series 10, allowing the beater to make contact immediately, made from 10mm thick steel, with a couple of HDPE blocks to protect the wheels. The robot was mostly held together using bolts rather than welding. This wedge gave the robot extra ground clearance at the front, although it was removed for its second fight in the series.

"A rather lacklustre effort comparatively I supose {sic} but as a reserve (not guaranteed a spot) and with only a few days and no money left a length of 10mm steel L channel was perfect front material."

— Harry Makes Things blog on the new front wedge

Side view of Hobgoblin in Series 10

Both versions of Hobgoblin suffered from not being able to run when inverted. The Series 9 version was theoretically invertible, but this failed to work in battle, so castor wheels were added to the top of Hobgoblin in Series 10. These allowed the robot to run inverted, although a combination of battery failure and melted castors still stopped Hobgoblin from moving freely while inverted.

"It seemed to love being on its back so much it spent the majority of its television career in the same position. DAMNIT GOB I BELIEVED IN YOU."

— Harry Makes Things blog

The Team

Team Hobgoblin in Series 9

Team Hobgoblin in Series 10

Team Hobgoblin was captained by 20-year old R&D designer Harry Hills, who was aged just 19 in Series 9. The lead designer of Hobgoblin, Harry Hills was responsible for the construction of the machine, and drove the robot in Series 9, where he was joined by 57-year old father Paul. For Series 10, Harry Hills recruited two roboteers with experience in lower weight classes on the UK live circuit, with Matt Smith and Andy Russell joining the team, with Matt Smith also becoming the driver of Hobgoblin. Harry Hills had previously designed the Series 8 version of Sabretooth, and was present at filming as part of Team Legion.

Qualification

CAD of Hobgoblin used to qualify for Series 9

Hobgoblin applied for Series 9 through open applications, with the build starting roughly 2 and a half months before the competition. Notably, Hobgoblin was one of very few robots to qualify for Robot Wars using purely a computer-aided design, as the build process was not finished at this stage - typically most robots are not selected unless there is evidence of the build progress. Harry Hills had only acquired motors for the wheels and weapons and a battery when his application was accepted.

"Somehow with enough smoke, mirrors and #buzzwords Robot Wars decided to accept my application. It was an amazing opportunity that I'm still stupidly grateful for, especially considering there were so many fantastic robots that didn't make the cut or pulled out due to time constraints. It was an honour to be a part of it."

— Harry Makes Things blog on qualifying for Series 9

Unused Hobgoblin concept designs, alongside the final CAD

This left Harry with just 6 weeks to build the robot, and the build finished just three days before the team had to drive to Scotland for the filming.

Due to Series 10 reducing the number of competitors from 40 to 30, Hobgoblin narrowly missed out on the initial selection of competitors, although it was invited to attend filming as a reserve entry. Once Point Blank withdrew due to safety concerns, Hobgoblin became the last robot to earn its place in the series, after Tauron and Coyote had also been substituted in.

"We had been waiting most of the day for Point Blank, the robot we were replacing to turn up. They did and after a few hours of rushing to finish their robot, a decision was made and we were in! It felt wonderful trundling all our gear over to the pit area to be alongside our friends at Magnetar and Coyote!"

— Harry Makes Things blog on qualifying for Series 10

Robot History

Series 9

"Heavyweights are stupid!"

— Harry Hills' catchphrase

Hobgoblin first competed in Heat B of Series 9, where it faced two powerful flipping weapons in Behemoth and Eruption, alongside Belgian entry Cobra, the sucessor to Dutch Robot Wars veteran, Pika. Before the fight, the team claimed that Hobgoblin could self-right in theory, but that this had not been tested. Additionally, the team encountered further worries, as changes to the robot's drive system instead made Hobgoblin incapable of turning, and its forward movement was limited - even entering the robot's starting position proved challenging.

"In an attempt to turn up/off the current limiting on the ESC to give the drive more grunt and must have turned it the wrong damn way. Bruh. Bruhhhhhhh. This turned it all the way down so the robot really struggled to move forwards and just noped at any attempt at turning. I found this out in the arena."

— Harry Hills

Hobgoblin is overturned by Eruption

Hobgoblin is left inverted

When the battle started, Hobgoblin quickly brought its weapon up to full speed, but its lack of speed meant that Hobgoblin could only meander around the arena. It was charged by Behemoth, although Hobgoblin survived this attack. However, Eruption then drove under it and flipped Hobgoblin over. Carried by the force of its egg beater, Hobgoblin came to rest beside the arena side wall and could not self-right, where it was counted out. After a full three-minute fight, Behemoth and Eruption were declared the victors, and Hobgoblin fell alongside Cobra.

Series 10

"It clicked when I was about fourteen, 'oh, I know how to take things apart!' Then the heavenly gates opened, and I was like... 'well, I can make stuff!'"

— Harry Hills on his gateway to robotics

Hobgoblin returned for Series 10 as a reserve entry, ultimately competing in Heat E as a substitute for the withdrawn Point Blank. In its Group Battle, it faced the new drum spinner from Team Ranglebots, Magnetar, and Team S.Tek's returning front-hinged flipper, Push to Exit. Hobgoblin entered the battle with its toothed front as protection against Magnetar's drum, despite knowing it would pose a disadvantage against Push to Exit.

Dara Ó Briain: "That thing at the front that spins, that's good, they're calling it the egg-beater, am I right?"

Harry Hills: "Oh yes, because if you chuck an egg into it, it'll get beaten!"

Dara Ó Briain: "Well yes, if you chuck an egg into most of our metal robots, the egg'll come off badly!"

Harry Hills: "...Let's not think about that!"

— Dara Ó Briain and Harry Hills on Hobgoblin's weapon

Hobgoblin is turned over by Push to Exit

Hobgoblin struggles to leave its own circumference

Hobgoblin drove forwards in the opening stages, quickly spinning up its egg-beater, but Push to Exit quickly drove under the toothed face of Hobgoblin, as the team had feared, and threw it straight over, causing Hobgoblin to skid over the flame pit. One of Hobgoblin's castor wheels had become damaged by fire, so Hobgoblin lacked the drive power to leave the area in which it had been flipped. Hobgoblin managed to edge nearer to the flame pit, but could only slowly turn in circles on the robot's one functional castor wheel, and an immobilisation clock begun, rendering Hobgoblin immobile, having lost the battle to Magnetar despite never making contact with the drum spinner.

"Hobgoblin, trying to turn through its own circumference, which means it would be just about mobile, are they?"

— Jonathan Pearce as Hobgoblin struggled to drive

Hobgoblin's message to Coyote

In the Robot Redemption Knockouts, Hobgoblin faced the runner-up of the Group Battle won by Thor, and the team's close friends, Coyote. Team Hobgoblin mockingly wrote "Bite Me, Coyote" onto their robot, surrounded by love hearts. However, one of Hobgoblin's batteries had shorted in-between battles, causing the power of the robot to drop from 16V to 4V, affecting Hobgoblin's other batteries in the process, which the team had not realised until entering the arena.

"A lot of my friendship groups are now robot-centred, and there were kind of a few of us who were the same age. We've almost kind of grew into it together."

— Harry Hills on the friendships between roboteers

Coyote chases the hindered Hobgoblin

After an opening collision between both robots, Hobgoblin was left reeling, and Coyote drove under the side of it to manoeuvre Hobgoblin towards the arena spikes. However, Hobgoblin was still struggling to gain control due to a slipped drive belt, and driver Matt Smith could not easily move his robot away from the raised pit.

"Probably a bad place to be..."

— Harry Hills

Hobgoblin eventually reversed off, and hit Coyote's jaw with its egg beater moments before Coyote's minibot Roadrunner opened the pit. Seemingly unable to drive directly forwards, Hobgoblin backed into Coyote, and was pushed into various sections of the arena, wedged by Coyote's lifter.

"Maybe try and gyro with the beater a bit? Can you do, like, hard turns on the diagonals?"

— Harry Hills suggests ways for Matt Smith to regain control

Hobgoblin is held over the flame pit

Coyote dragged Hobgoblin near to the centre of the arena, where Hobgoblin managed to rip some pipework from Coyote, but it could not leave its own circumference before Coyote drove it into the reach of Sir Killalot, although Hobgoblin was able to buckle and damage the House Robot's claw. Coyote held Hobgoblin over the flame pit, and pulled away a drive belt from Hobgoblin, while Hobgoblin failed to move away from its position, eventually shearing a keyway in the robot's drive. Coyote edged Hobgoblin into the CPZ, and the damaged Sir Killalot left in order for Shunt to barge in, driving Hobgoblin into the corner of the arena and repeatedly strike it with axe blows, striking both the robot and the egg beater itself.

"That's us spent, pretty much."

— Matt Smith

Hobgoblin tears Shunt's axe blade off

Although Hobgoblin was immobile, and Shunt landed further axe blows, Hobgoblin managed to earn some vengeance, as when Shunt landed a direct blow on Hobgoblin's spinning weapon, the egg beater ripped the entire titanium tip from Shunt's axe, shattering it across the arena. While Hobgoblin was being counted out, Shunt flipped Hobgoblin over using its scoop, and left it in the corner of the arena until 'cease' was called. Hobgoblin was eliminated at this stage, but left the competition on a high note.

"And Hobgoblin comes away with a little minor moral victory there!"

— Jonathan Pearce

Results

Wins/Losses

• Wins: 0
• Losses: 3

Series Record

Series	Hobgoblin Series Record
Series 1-7	Did not enter
Series 8	Entered with Sabretooth
Series 9	Heat, Round 1
Series 10	Heat, Round 1

NOTE: Team member Matt Smith attempted to enter Series 8-9 with Phantom, and Series 10 with Crowd Control, but was never selected to compete.

Gallery

3D printed models of Hobgoblin

Hobgoblin enters the arena during Series 9

Hobgoblin in the pits during Series 10

Hobgoblin in the arena during Series 10

The 'Don't Panic, Try Not to Die' message

Unused designs for Hobgoblin

Outside Robot Wars

Hobgoblin

Hobgoblin did not make a combat appearance again after its time on Robot Wars, and has remained with teammate Matt Smith since this time. Hobgoblin was among various former Robot Wars competitors which appeared at Robonerd as a static display in September 2018.

Harry Hills

Before involving himself with heavyweight robots to compete on Robot Wars, Harry Hills mostly participated in featherweight competitions prior to the show's reboot. Featherweight robots built by Harry Hills include two versions of Flatpack, a four-bar lifter, and Massacre, an overhead bar spinner built in 2014-15.

Flatpack (featherweight)

Flatpack (featherweight)

Massacre (featherweight)

Massacre (featherweight)

A six-wheel driven pushing robot

Raptorweight drum spinner

Thinking with Portals (featherweight)

Thinking with Portals (featherweight)

Hypno-Disc replica (antweight)

King Buxton 20 (heavyweight)

Various machines made by Harry Hills

Harry Hills has also built a number of antweight robots, including a 150g replica of Hypno-Disc, and also started to build a raptorweight robot armed with a drum spinner. Due to a lack of raptorweight competitions, Harry Hills sold the drum spinner to Thomas Long for use in Halcyon, and instead used the raptorweight as a prototype for his third featherweight, Thinking with Portals. This was a 13.6kg clusterbot made up of identical, near-invertible robots armed with egg beater spinners. Harry Hills also built the featherweight robot GERTY for Rachel Gibson.

Harry Hills later helped Simon Harrison to build King Buxton 20, and competed as part of the team at RoboGames 2018, where it was defeated by the experienced Touro Maximus and Megalodon. The pair collaborated to design a new eggbeater heavyweight, Monster, which was submitted to, but not selected for an unspecified season of King of Bots. Monster would ultimately not materialise beyond CAD drawings prepared by Hills from a concept devised by Harrison. In 2021, both would unite once again to form Team Sabotage along with Mark Mellors and Jamie McHarg, who applied for that year's season of BattleBots with Hoodlum. A four-wheel drive heavyweight armed with an undercutter (depicted in one render as a four-toothed blade paying homage to Pussycat's weapon), Hoodlum would not be selected for that season, a matter confirmed by the King B Facebook page in May along with its planned design.

Aside from combat robots, Harry Hills has also worked on a number of RC car projects.

Matt Smith

Matt Smith is a former owner of Eric from the original series, with success in the beetleweight category. Matt Smith has also been in possession of Hobgoblin since Series 10 was filmed, although Harry Hills still owns the machine. For more information on Matt Smith's excursions outside of Robot Wars, see Phantom.

Andy Russell

Pendulum in 2016

Andy Russell is primarily a roboteer in the featherweight division. His first robot was Push and Shove, a ramming robot which reached the Top 6 of the UK Featherweight Championship. Russell's second robot was Ion a beetleweight robot armed with a spinning drum, where the weapon motor was housed. Adam Russell's next project was Pendulum, a robot armed with a 3.2kg TOOLOX 'egg beater' which spins at 6000rpm. The robot was protected by single piece billet aluminium wheelguards. At the UK featherweight championship in 2016, Pendulum won all of its round robin battles bar two (both of which were against the eventual champion Explosion) and defeated Tormenta at the UK Featherweight Championship in 2016, winning the majority of its round robin battles. Andy Russell also created Ion's successor, Ion 2, at a later stage.

Push and Shove

Ion

Pendulum in 2018

The first version of Telekinesis

Telekinesis 1.5 at King of Bots UK

Andy Russell next built Telekinesis, an invertible undercutter using watercut HARDOX armour, which competes to this day, occasionally referred to as Telekinesis 1.5. Its discs are interchangeable, including a bar spinner configuration. At the King of Bots UK Featherweight Championship, Telekinesis won its first battle against Little Devil and Nigel Barrage by knockout, but lost its second melee to Tempest, finishing second. Telekinesis lost its Judges' decision against Nelly the Ellybot, but after finishing second place again, Telekinesis qualified for the Top 20. However, it withdrew prior to its battle with Little Devil, and was replaced by Orpheus, eliminating Telekinesis at this stage.

Telekinesis in July 2019

A repainted silver Telekinesis competed at the Robodojo Autumn Featherweight Championship in November 2018. It lost its first battle after driving onto the lip of the pit, and collected a win by default over X-303, but ultimately withdrew due to a lack of spare wheels. Telekinesis returned for the January 2019 event, and lost its first two fights, driving into the pit and then losing its removable link in each fight; however, Telekinesis redeemed this by causing significant damage to Get Shrekt, forcing it to retire from the event, and also defeated P.I.P. to earn fifth place in the full combat class. At the March 2019 event, Telekinesis suffered an early loss to Plastic Fantastic, but collected three straight wins against Binky, Vega and Raving Luna-Tic to qualify for the third place play-off, losing to Graffiti there as its spinner was not working. Telekinesis had an unfortunate run at Robodojo in July 2019, suffering defeats to Sawcerer, X-303 and Get Shrekt. It would continue to compete at Robodojo in the following years, as recently as January 2023.

Telekinesis 3 in August 2019

For the UK Featherweight Championship in 2019, Andy Russell built a third version of Telekinesis, sporting a new yellow blade. Although it earned destructive victories over Frycook and Red Hot Tilly Pecker, it was forced to withdraw from battles against Captain Jack Spinnah and Galaga, and was resigned to fourth place in its group after losing to Venator 3. Nevertheless, Telekinesis competed in the Annihilator where it achieved third place. Telekinesis also competed in every edition of Labman FightFest until 2024, finishing fourth in the Annihilator Cup at the FightFest Winter Challenge, and finishing fourth place overall in the main 2023 championship under Rachel Gibson and Brooke Reay.

Semtex

In 2022, Andy Russell would build the 6.4kg drum spinner Semtex, which won the Hobbyweight Championship at FightFest that year, and also competed in the 12lb division in Norwalk Havoc Robot League with mixed success. It would return to the FightFest Hobbyweight division in 2024.

Nitro

Semtex would later be upscaled to a featherweight design, with Andy Russell building Nitro in 2024. This would prove to be Andy Russell's most successful robot to date, winning every individual Robodojo live event of the year to take the overall title, critically also winning the FightFest heavyweight competition in 2023, defeating Killi Pepper in the Grand Final, and its own predecessor Telekinesis in the prior round. Nitro would also compete at NHRL in 2024, qualifying for the December Grand Final.

In 2023, Andy would make a Beetleweight vertical spinner named Propane, which notably uses a counter-gyro vert to help it with turning. It has proven to be successful, notably winning the BBB Beetle Brawl 2024.

Andy Russell often assisted Adam Hamilton with the creation of commission-based robots, and both competed as part of Team Immersion in the Chinese show This is Fighting Robots with the heavyweight Bonfire. Andy Russell also joined Team RC Kev to compete in King of Bots II with Switch.

Jäger at the 2021 season of BattleBots, including Toe Kicker (right) built by Andy Russell

Big Dill at BattleBots World Championship VII

To compete in the planned 2020 season of BattleBots, Andy Russell joined a German-led team to enter the show with multibot Jäger, though had to withdraw due to the COVID-19 pandemic. For the project, Andy Russell built a scaled-up version of Telekinesis with various undercutting spinners, which could also fight as a legal UK middleweight. Andy Russell was to be the team captain of Jäger in Season 6 of BattleBots, but this role soon returned to Ralf Schneider after travel restrictions prevented all British roboteers from attending the filming. Andy Russell's robot would be named Toe Kicker at filming and was driven by Emmanuel Carillo, driver of Big Dill. In its first fight, Jäger fought P1, although Toe Kicker was forced to largely fight alone after the other half of Jäger (Arm Muscle) was disabled early on, with P1 eventually stranding Toe Kicker against the Upper Deck for a win by knockout. Jäger was also unsuccessful in its second fight against Captain Shrederator, ending its season at an 0-2 record. Jäger was not selected to compete in the following season, though Andy Russell did attend BattleBots for the first time as a member of the Big Dill team.

Trivia

The 3D printed model of Hobgoblin, sold on eBay in 2024

• Before setting on the design, Hills had also created CAD renders of an invertible Hobgoblin with an egg beater, and a version with an undercutting spinner.
• During the construction of Hobgoblin, Harry Hills 3D printed two scale models of Hobgoblin based on his CAD designs.
  • In August 2024, one of these models was listed for sale on eBay.
• Hobgoblin and its builder contribute two key elements of the introduction to every Series 9 episode. Harry Hills spoke his "don't panic, and try not to die" motto, while Hobgoblin's beater was also dropped onto a table in video footage taken from the team's unused VT.

External Links

• Harry Makes Things blog - Hobgoblin Series 9 build log
• Harry Makes Things blog - Hobgoblin Series 10 build log
• Harry Makes Things Facebook page
• Hobgoblin (Series 9) on the Robot Wars website
• Hobgoblin (Series 10) on the Robot Wars website