- "It's the bad boys of the Seventh Wars!"
- — Jayne Middlemiss on Gravity's team
Gravity was a Dutch robot that competed in Series 2 of Dutch Robot Wars and Series 7 of the UK Robot Wars. In the latter, it comfortably reached the Semi-Finals, defeating the seeded 13 Black and Dantomkia in the process, before finishing in the top eight after losing to then-reigning champion Tornado. Gravity was the first robot to overturn Dead Metal, as well as being the only robot to flip Growler and Cassius Chrome over. It also broke the shortest battle record by flipping Dantomkia out of the arena in 5.8 seconds during the Series 7 Semi-Finals, and was the most successful international robot ever to compete in the UK series.
Versions of GravityEdit
Gravity (Dutch Series 2)Edit
- "Robot was working almost perfect, only thing that didn't work was the valve to fire the flipper... I used a normal hydraulic valve, and worked fine when testing @ 20 bar... But at full pressure in the uk arena it just didn't work. Or simply just opened, and didn't close."
- — WJ Dijkstra on the flipper of Gravity from Dutch Series 2
The first televised version of Gravity competed in the second series of Dutch Robot Wars. It was a polycarbonate box-wedge with a pneumatic flipping arm, which lay flush to the floor with decent lifting power. Gravity was quick, and for a two-wheel driven robot, it had extreme pushing power. However, it had a high ground clearance, it could not self-right, and its polycarbonate armour was highly destructible. The robot somewhat resembled the loanerbot entered as The Green House and Vert-I-Go.
Gravity 3 (UK Series 7)Edit
The version of Gravity seen in Series 7 was the third iteration of the machine, known by the team as Gravity 3, but simply named Gravity on the show. Resembling a snowspeeder in shape, Gravity's main weapon was an extremely powerful full-pressure flipper, easily capable of flipping in excess of 300 kilograms (as demonstrated by overturning Growler and Cassius Chrome) and driving through a car at speeds of 10 mph. It ran through two half-inch Burkert valves, fed by 2 litre full-pressure buffer tanks. The armour, on the other hand, was less resilient, with both its inflatable tyres also proving to be a weakness in its main competition loss. Gravity's front wedge was very low to the arena floor when grounded, although the wedge would often rise from the floor when Gravity moved from a standstill, due to Gravity's two-wheel drive system, consisting of 10" competition go-cart wheels driven through a 20:1 dual stage gearbox.
- "Ok guys, You've read the story, Gravity 2 worked pretty good, but pretty good is not good enough for me. So, enter Gravity 3 ! Hmm, where to start... I liked the front end of Gravity 2 , so that's the only thing I kept. Just angle grinded everything else off. I tilted the gearboxes to make more room in the back for electronics and the Co2 bottles. Because the last flipper arm bent, I had to make a new one. The new one is made from 2 lengths of 60x30x3mm mild steel, the scoop is 5 mm mild steel. The hinge is made from a thickwalled tube and 2 m24 bolts, very basic but it works."
- — WJ Dijkstra on advancing from Gravity 2 to Gravity 3
Gravity's pneumatics system was loosely based on that of Dantomkia, as Dantomkia had participated in a Dutch Robot Rumble and been stripped down as part of a workshop to help the Dutch roboteers. The use of buffer-tanks, multiple inlet 1/2bsp valves and the giant high pressure 100mm bore 180mm stroke ram combined with the uncoupled flipper arm was a first, and spawned many successful copies and derivatives.
- Main article: WJ Dijkstra
Team Captain WJ Dijkstra originated from Project One, before temporarily splitting from the other members of Team Mad Science for Series 2 of the Dutch Wars, which he entered alongside Mark Nievelstein, who joined the team after WJ Dijkstra sold the position on a public forum. WJ Dijkstra built Gravity alone, with only the 63m bore 220mm stroke ram and the unfortunately misused hydraulic 4/2 valve being provided by former teammate Mario "Maddox" de Jongh, and the Bosch 750w drivetrain being provided by Jeroen van der Loo of Team KODOX.
During Dutch Series 2, WJ Dijkstra also teamed up with Jeroen van Lieverloo from Impact and Alex Ruschen from ODT-Zero to create the three way clusterbot √3, with each team member entering an individual featherweight and joining for the clusterbot. For the UK Championship in Series 7, WJ Dijkstra rebuilt Gravity, but as Jeroen van Lieverloo and Alex Ruschen did not have their own robots ready, WJ Dijkstra offered them each a place on his own team, as they had become good friends through competing with √3.
Jeroen van Lieverloo would eventually become the owner and captain of the Gravity series, and reinvited WJ Dijkstra and Alex Ruschen onto his team for Series 8, but Gravity 5.7 was not chosen to compete, nor did the team of three return for the following series.
Gravity qualified directly for Dutch Series 2 through open applications, due to the low number of applicants for the series, and WJ Dijkstra's experience as a returning roboteer, having competed in Series 1 with Project One.
- "We had to wait several hours before we could get on the ferry so we did some driving around with Gravity in the parking lot. This was the third version of Gravity and WJ had got everything right on this one. It drove perfectly. The shape was great and, in theory, the flips would be next level. Eventually, we boarded the ferry, and the next day we drove up to the qualifiers. There was already a long queue of cars waiting to get in. We were so excited!"
- — Jeroen van Lieverloo on arriving at the Series 7 qualifiers
Gravity fought an impressive qualifier for Series 7 of the UK series alongside fellow European hopefuls Mechaniac and RCC 2, as well as a representative of Richard Huish College. It caused the latter to become briefly immobile with a single strong flip, and then pushed the other two around. It self-righted when flipped by Mechaniac, and threw Mechaniac towards the arena entry gates, flipping it and the British spinner again afterwards. Gravity won the battle, the only robot to qualify for the main competition. WJ Dijkstra also offered Jeroen van Lieverloo a place on his team, after his robot Impact 2 withdrew from its qualifier battle.
- "After the buzz had been building around Robot Wars 8, I immediately started planning Gravity 5.7. It needed a fresh, new look and a new frame. I sent in the application and, in my mind, I was already accepted. After all, it was the legendary Gravity! But I hadn’t taken into account that Gravity had evolved into a typical wedge-shaped flipper and, let's be honest, there were probably a lot of wedge-shaped flippers in the Robot Wars applications, especially as the live circuit had nurtured them."
- — Jeroen van Lieverloo on applying for Series 8
Ahead of the rebooted UK Series 8, the current owner of Gravity, Jeroen van Lieverloo, sent in an application for Gravity 5.7 to compete in the series, also inviting WJ Dijkstra and Alex Ruschen back onto his team, with WJ Dijkstra being the robot's driver again. Gravity 5.7 was a more conventional wedge-shaped flipper design, which boasted less flipping power on the live circuit in comparison to the Series 7 competitor Gravity 3. Jeroen van Lieverloo completed an online application for Gravity, and created a new frame for the robot. However, despite the team presuming that Gravity's legacy in Series 7 would be grounds for it to qualify, they had not considered the possibility that Gravity had evolved into a design which did not stand out from other wedge-shaped flippers. Although Jeroen van Lieverloo initially received an email stating that his team had qualified for Series 8, this was a mistake, as the intended recipient was Jeroen van der Loo, and Gravity was not selected for the series. Jeroen van Lieverloo went on to compete alongside Jeroen van der Loo with Tough as Nails, while WJ Dijkstra and Alex Ruschen did not compete.
- "So the waiting game went on. I sent in updates about how the build was going. The waiting game continued, well past the point where I thought it would, and I started getting news from builder friends that they “could not comment on their application status”. And then it finally happened; I got an email about being accepted! But there was something weird in the language. It seemed like a follow-up email to a phone call and I had not received a phone call. After a few minutes, I had figured it out. It was a mix-up. My name is super similar to Jeroen van der Loo, someone I travel with and we help each other a lot. But he is the brains behind Tough As Nails, not me, and a little birdy had told me that Tough as Nails had already been accepted. So I emailed back explaining the mistake and the nice lady apologized sincerely. She was also able to tell that Gravity had not been accepted. After I told Jeroen the news, he invited me onto his team and I helped out with the work that needed to be done on Tough as Nails."
- — Jeroen van Lieverloo on Gravity being declined from Series 8
Team Tie-Rip planned an upgraded Gravity 6 for Series 9, but decided not to apply due to time constraints, and Jeroen van Lieverloo instead joined Team Rubbish to compete with Cobra, and then his own machine THE BASH in the World Series, part of Series 10. WJ Dijkstra and Alex Ruschen are not known to have applied for either series.
Dutch Series 2Edit
Gravity's first battle was against Das Gepäck.
Das Gepäck slammed Gravity into the wall, but Gravity was able to get underneath and lift Das Gepäck with its arm. It pushed Das Gepäck into the wall and pinned it before driving it into Sgt. Bash's CPZ and flipping it over. Das Gepäck escaped, but Gravity caught it and again forced it into Sgt. Bash's CPZ, this time flipping it up against the wall. Sgt. Bash freed Das Gepäck, and time ran out, meaning the jury would be called upon to make a decision. They ruled in favour of Gravity.
- "Gravity is a matter of perspective"
- — Sticker on Bloody Murder Weapon
In the next round, Gravity faced Bloody Murder Weapon.
Gravity's flipper was not working, but its pushing power was sufficient enough to push Bloody Murder Weapon into Growler's CPZ. After Growler released it, Gravity simply pushed it in again. Gravity tried twice more to push Bloody Murder Weapon into a CPZ, but Bloody Murder Weapon escaped unharmed. Persistently, Gravity pushed Bloody Murder Weapon into a CPZ again, and this time Sir Killalot picked up Bloody Murder Weapon and spun it around the arena, releasing it just as the clock ran out. The jury's decision was, predictably, in favour of Gravity.
In the Heat Final, Gravity faced Scrap-2-Saur.
It managed to dodge Scrap-2-Saur's flipper for a few moments, but Scrap-2-Saur eventually got underneath and flipped it. It righted Gravity immediately after, only to flip it again. Gravity's flipper was still not working, so it was defenceless as Scrap-2-Saur pushed it into the CPZ, where Dead Metal sliced through its tyres. Gravity was counted out, and Matilda charged in with her flywheel, destroying Gravity's left side and tearing out its internals. Gravity was placed on the floor flipper, and the force of the flip caused Gravity's CO2 canister to separate from its hose and go skittering across the arena, propelled by its rapidly escaping gas. The CO2 canister eventually fell into the pit, followed shortly by Gravity.
- "Technical ****ing knockout!"
- — Eric Corton's assessment of the situation
UK Series 7Edit
- "The bad boys of the Seventh Wars..."
- — Jayne Middlemiss on Gravity
Gravity made a tremendous start to its heat as it went up against Hydra, Thor, and Hodaf the Bad in Round 1. As both teams were in the same control booth, Gravity's team intended to team up with Hodaf the Bad, against Hydra and Thor.
Gravity immediately charged at Hydra and tossed it high into the air with ease. As it came in for a second attack, Gravity missed with its flip, turning itself over, but rolled back onto its wheels after being flicked by Hydra. Gravity then pursued the fleeing Hydra across the arena, before briefly turning to attack Thor, but they were unable to get under Thor's front wedge. Instead, Gravity picked on Hydra again, flipping their opponent and sending them spinning through the air again.
- "Gravity's after Hydra, though, you can tell, can't you? Has it against the arena wall! Oh, goodness me! Has destroyed the sidewall!"
- — Jonathan Pearce as Gravity flips Hydra into the arena wall
As Hydra attempted to turn over Gravity with its lifting arm, Gravity flipped them once more, in an attempt to throw it out of the arena, causing it to land on the arena wall and destroy a section of it. Gravity then threw Hydra from the arena and into a camera, breaking it, before 'cease' was called for safety reasons. Not hearing the original 'cease', the team continued fighting, and flipped Thor over Refbot, causing its hammer to become stuck in Refbot until 'cease' was called for a second time. The judges marked the criteria up until the first 'cease' was called, and Gravity moved through, along with Thor.
- "In our episode, we were referred to as “the bad boys of Robot Wars” but the show did not air the reason for the nickname. Our first broadcast fight was a rumble where we were up against Thor, Hydra and Hodaf the Bad. We were sharing the control booth with the guys from Hodaf so there was some collaboration between us. We would go for Hydra and they would go for Thor. For the most part that is what happened, until the moment where we broke the arena side wall and threw Hydra onto a camera (which was the second one we broke…remember the√3 fight?) Apparently, a cease was called at that point. We honestly did not hear it and continued the fight. We flipped Thor OVER the Refbot and it got its axe stuck in the back of the house robot. Then a member of production stormed in our booth and yelled that we must stop! We really did not hear the “cease” but we were told we were in serious trouble and could face disqualification. We got a seemingly scripted safety speech from Derek Foxwell (the senior technical consultant) with the cameras rolling. Looking back at it, it was probably all for the benefit of the show. But they did test the loudspeaker in our booth for correct function, and volume was cranked up much higher for the next fights."
- — Jeroen van Lieverloo
In the second round of the heat, Gravity went up against the seventh seeds, 13 Black.
Gravity was by far the more aggressive robot, and 13 Black spent much of the battle upside down after just one flip from Gravity. After a while, Gravity pushed 13 Black into a CPZ and began spinning around in the middle of the arena, celebrating with its flipper open.
- "What a good, early attack again by Gravity. This is certainly the best machine we've seen out of Holland ever in Robot Wars."
- — Jonathan Pearce as Sir Killalot parades 13 Black around the arena
Meanwhile, Sir Killalot came in and righted 13 Black, prompting Gravity to attack 13 Black again, missing this time and lifting Sir Killalot instead, before flipping their opponent and accidentally throwing the previous Semi-Finalists out of the arena, eliminating them.
It is known that before the heat final, and possibly before the semi-final, Gravity had to lower the power of its flipper. This may have come as a result of Gravity damaging the arena wall and camera in its first battle, and this may also explain why Gravity did not attempt to throw Lightning out of the arena in their Heat Final.
Lightning had suffered a puncture prior to entering the arena and could not escape Gravity's onslaught. Gravity came in for a second attack, but missed and nearly turned itself over instead. The two competitors then became locked in a push-and-shove match, with Gravity causing minor damage to Lightning in the process. Eventually, Gravity was able to get another flip in on Lightning, immobilising Lightning in the process. Gravity continued to flip the beaten machine, before Refbot came in to count Lightning out.
- "I'll go one further from my earlier statement. This is not just the best machine to come out of Holland, but out of the whole continent I think, to fight in Robot Wars so far."
- — Jonathan Pearce as Gravity flips the immobile Lightning for the penultimate time
To celebrate, Gravity then flipped Shunt with ease, and then turned Dead Metal over after some difficulty, leaving Refbot as the only other mobile machine. Refbot showed Gravity the red card, but Lightning was already counted out, and so Gravity progressed to the series Semi-Finals.
- "It's taken them all on, and beaten them all! Watch out for Gravity later in the series. It could go all the way, but for now, Refbot, red carded! Cheeky little blighter!"
- — Jonathan Pearce after Gravity had caused enough trouble
In the first round of the Semi-Finals, Gravity was placed up against the fifth seed Dantomkia, the robot that WJ Dijkstra feared the most out of all the other series semi-finalists.
However, when the battle started, Gravity very quickly slid underneath the side of Dantomkia's wedge and rushed over to the arena side wall with Dantomkia stuck on Gravity's wedge, throwing it out of the arena in 5.8 seconds, setting the record for the shortest battle in the UK series which had previously been set by Dantomkia. This remains the fastest battle of the original run of Robot Wars, and the second-fastest in the show overall.
- "That stunned even them! They can't believe it!"
- — Jonathan Pearce on the reaction of the quick battle
This quick victory put Gravity up against the reigning champions, Tornado, in the second round of the Semi-Finals.
In this battle, Tornado was the quicker machine, and slammed Gravity into the arena wall and then into Sir Killalot's CPZ. Gravity sustained a tyre puncture from Sir Killalot's claw, and was clearly hobbling as Tornado continued to push it around the arena. Gravity finally got underneath Tornado and flipped it high into the air and upside-down. Tornado shoved Gravity again, but Gravity flipped Tornado the right way up. Tornado activated the pit release button and pushed Gravity onto the pit just as it was opening, and Gravity fell into oblivion.
- "And Gravity are on the pit, and caught there. And descending away from the Seventh Wars."
- — Jonathan Pearce as Gravity's reign of terror ends
Tough as Nails pitted Scraptosaur in the opening seconds, before Gravity could even become involved. Gravity and Tough as Nails then waged a fairly even contest, where Tough as Nails would ride over Gravity's wedge and throw itself around the arena, whilst Gravity mostly missed with its flips during these encounters - at one stage resulting in Gravity overturning itself, forcing it to self-right. Both robots were plagued by the presence of Refbot in this fight, which interrupted attacks from both parties. After Tough as Nails held a brief grip on Gravity, the flipper of Gravity was used to launch Tough as Nails backwards with a big flip. However, once Tough as Nails escaped, it grabbed Gravity from behind, and took it to the pit, dropping it in to eliminate Gravity ahead of the Third World Championship.
Gravity also participated in the last battle to be filmed in the Robot Wars Arena prior to the series' 12-year hiatus, the House Robot Rebellion, competing alongside Behemoth. Having previously defeated Shunt and Dead Metal, Gravity was now able to challenge Cassius Chrome, Growler, and Mr. Psycho.
- "Gravity thinks he can take on our dog of war...Oh! And he can!"
- — Jonathan Pearce as Gravity overturns Growler early on
Gravity was rammed by Growler in the opening seconds, but recovered and flipped Growler onto its back fairly quickly. Meanwhile, Behemoth activated the pit just as Cassius Chrome drove over it. Gravity used this opportunity to flip Cassius Chrome onto its side over the pit, but Refbot would later free the trapped House Robot.
Gravity tried to attack Mr. Psycho but could not flip it, and the colossal House Robot smashed Gravity with its hammer, immobilising it. Behemoth attempted to use the motionless but still actively armed Gravity as a weapon against the House Robots, but Behemoth struggled to push Gravity forwards, and Cassius Chrome shoved them apart. Mr. Psycho had become immobile during the battle, leaving only Cassius Chrome and Behemoth active at the end of the five-minute battle. The audience decided that Behemoth and Gravity were the winners of the House Robot Rebellion. Later on, the damage caused by the hammer blows from Mr. Psycho was revealed to be nothing more than the long antenna dropping from the supporting tube into the robot. The sensitive failsafes of the Mythras speed controllers didn't accept the radio controls any more, but the RC switch that commanded the flipper remained functional.
- "For those who don’t know, we lost drive when the receiver cable broke after a freak hit from Mr. Psycho which meant that the fail safe shut down the drive. The flipper relay was still working though and Behemoth did its best to push us at Mr. Psycho even when we were dead!"
- — Jeroen van Lieverloo
|GRAVITY - RESULTS|
|Heat D, Round 1||vs. Das Gepäck||Won|
|Heat D, Semi-Final||vs. Bloody Murder Weapon||Won|
|Heat D, Final||vs. Scrap-2-Saur||Lost|
|The Seventh Wars - UK Championship|
Semi-Finals, Round 2
|Heat D, Round 1||vs. Hodaf the Bad, Hydra, Thor||Qualified|
|Heat D, Round 2||vs. 13 Black (7)||Won|
|Heat D, Final||vs. Lightning||Won|
|Semi Final 1, Round 1||vs. Dantomkia (5)||Won|
|Semi-Final 1, Round 2||vs. Tornado (1)||Lost|
|The Third World Championship|
Representing the Netherlands, Eliminated in Qualifiers
|Qualifier||vs. Scraptosaur (NED), Tough as Nails (NED)||Eliminated|
|House Robot Rebellion|
Competing with Behemoth
|House Robot Rebellion||vs. Cassius Chrome, Growler & Mr. Psycho||Won|
- UK Wins: 5
- UK Losses: 2
- Dutch Wins: 2
- Dutch Losses: 1
|Dutch Series||Gravity Series Record|
|Series 1||Entered with Project One|
|Series 2|| Heat Final|
Entered with √3
|Series||Gravity Series Record|
|The First Wars||Did not enter|
|The Second Wars||Did not enter|
|The Third Wars||Did not enter|
|The Fourth Wars||Did not enter|
|The Fifth Wars||Did not enter|
|The Sixth Wars||Did not enter|
|The Seventh Wars||Semi-Finals, Round 2|
|Series 8||Not selected|
|Series 9||Did not enter|
|Series 10||Did not enter|
Outside Robot WarsEdit
Although the original Gravity competed in Dutch Series 2, and Gravity 3 competed in UK Series 7, Gravity 2 was not seen on television. It greatly resembled Gravity 3, serving as a prototype to its successor. Gravity 2 competed at the Dutch Robot Games in 2003, and boasted similar flipper power to Gravity 3, but lost all three of its rumbles to Tornado, Tough as Nails and Hard.
- "Ok guys, You've read the story, Gravity 3 worked pretty good, but pretty good is not good enough for me. So, enter Gravity 4 !... You'd think... But instead of making a bigger, better, bolder version, I sold Gravity 3 and built a cheep downgraded version of Gravity, jut to be able to go to 2 live-events in the UK ! I started with gathering all the stuff I had laying around. Decided to use what was left of the frame of Gravity 1, because that what give me some more time in building the rest of the robot. Added 2 nice wheelchair motors with the gearboxes attached, made a mounting platen and bolted them on."
- — WJ Dijkstra on building Gravity 4
Meanwhile, WJ Dijkstra continued to build Gravity machines, first creating Gravity 4 from the remains of the original Gravity machine, a cheaply-constructed robot built simply so WJ Dijkstra had a robot to compete in UK live events with, which he did at two separate events. WJ Dijkstra planned a Gravity 4.5 after this, and would finally build Gravity 5, which would become Gravity 5.2, and competed over the 12-year hiatus of Robot Wars, also attempting to qualify for Series 8 of Robot Wars.
Robot Wars Live EventsEdit
Due to Gravity 5.2 coming from the Netherlands, it has only appeared irregularly at the Robot Wars Live Events. It first competed in the second live event of the new Robot Wars Live Events at the Robot Wars Championship event at Portsmouth in March 2013. It fought Ripper and Meggamouse in the heats, putting in a strong performance but losing the judges' decision after getting flipped repeatedly by Ripper. It also took part in a separate European Challenge battle against two German robots, Tsunami and Luzifer, therefore being the only Dutch robot in the fight. It got a flip in on Tsunami, but one of its wheels broke off afterwards, immobilising it.
In 2015, Gravity performed well at the Robot Wars World Championships, held in Colchester. It was the last robot left standing in its first round battle, as Gripper was flipped over, and Ripper became stuck in the wall structure, before Gravity pushed the eventual champion Toxic 2 into the pit, despite Toxic 2 qualifying regardless. In the second round, Gravity fought Tiberius and Kan-Opener, the latter breaking down in the opening seconds. Gravity spent the full three minutes fighting a head-to-head battle with Tiberius, where it suffered from a long period of crushing, puncturing Gravity's tyre, but Gravity still won the Judges' decision after flipping Tiberius several times. Gravity entered the quarter-finals with a tyre on top of its flipper for extra protection. It survived a long period of time against Gabriel, flipping Gabriel around and briefly stranding it on its wheel, but Gravity received blows from Gabriel's sword throughout. Gravity became immobile as a result of flipping itself over, and locking its flipper open when trying to self-right, which stranded Gravity on its back end, leading to Gabriel winning the Judges' decision.
- Gravity was one of the two competitor robots to fight in the final ever battle filmed in the Robot Wars Arena before the show took a 12-year hiatus, fighting alongside Behemoth in the House Robot Rebellion.
- Every House Robot except Matilda was flipped by either Team Firestorm (including Sir Killalot's fall with GroundHog) or Gravity.
- Both of Gravity's Championship appearances were in Heat D.
- Gravity was one of only four robots to enter multiple side events in Series 7, alongside Behemoth, Flippa and Kat 3.
- Like Anty B, there was a model of the robot which only competed in live competitions.
- Gravity held the record for the shortest battle in televised Robot Wars competition, throwing Dantomkia out of the arena in 5.7 seconds during their Series 7 Semi-Final battle. This record was later broken by Rapid in the Heat Semi-Finals of Series 10, Heat 3, where it threw Track-tion out of the arena in just 5.6 seconds. The record was also broken by Kronic in March 2012, which defeated Iron-Awe at a Roaming Robots event by throwing it out of the arena in just 4 seconds - the shortest battle in all FRA-sanctioned competitions.
- In 2007, Gravity received an Honorable Mention in The Combat Robot Hall of Fame, in recognition of the Series 7 version's powerful flipper and its influences on European robot combat design.
|First competitor robot to flip over Dead Metal|
|Only competitor robot to flip over Growler|
|Only competitor robot to flip over Cassius Chrome|
|Best competing international robot in the UK Championship|
- ↑ http://members.chello.nl/~wj.dijkstra/robotics/grav1.htm
- ↑ http://members.chello.nl/~wj.dijkstra/robotics/grav3.htm
- ↑ https://www.facebook.com/TeamTieRip/posts/729934040672368?__tn__=K-R
- ↑ https://www.facebook.com/TeamTieRip/posts/665597410439365
- ↑ https://www.facebook.com/groups/UnofficialRobotWars/permalink/706047689674999/
- ↑ https://web.archive.org/web/20060128030110/http://www.dutchrobotgames.nl/cgi-bin/pda
- ↑ http://members.chello.nl/~wj.dijkstra/robotics/grav4.htm
- ↑ http://runamok.tech/hall_of_fame.html