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"At one-and-a-half meters, this is the longest 'bot in the field. Its hydraulic front lift can in theory hoist a tonne. A rear blade protects the four rear wheels, its front blade also carries one-and-a-half inch spikes. Powered by two 24 volt wheelchair motors, protected by an aluminium steel and steel chassis."
Jonathan Pearce introduces Kill Dozer

Kill Dozer was a competitor on Robot Wars, competing solely in The Second Wars. Though it lost its only battle, Kill Dozer is most notable for holding off Matilda in the Tug of War trial, while every other robot competing in the Heat Trial was pulled into the Pit.

Design[]

"Most of the robots last year had reasonable armour and this year the armour would probably be better, therefore most cutting weapons would not damage robots enough to completely disable them. As oxyacetylene weapons were not allowed something to flip our opponents over was the next best option."
— Paul Hart on deciding to use a lifting weapon[1]

The insides of Kill Dozer

Kill Dozer was a rectangular box-shaped robot with a large hydraulic lifter on the front, which could hoist a ton in theory (realistically it could lift in excess of 12 stone) and featured 1.5' spikes to cause ramming damage to wooden robots. There was also a blade at the back to protect the rear wheels, also powered by hydraulics. The lifter was powered by an electric pump from a Ford Granada ABS, giving 160 bar (around 2400 PSI) of lifting power. An electric motor was used to release the pressure by opening and closing a valve.

Kill Dozer in the arena

The robot was built over four months, at a cost of roughly £567, with many parts being sourced from skips, friends or the team members houses to save money[2]. It was armoured in aluminium with a steel chassis. To save weight, the chassis used steel tubing, taken from bench legs found in a skip. The aluminium armour was also from old equipment panels found in a skip.

"We needed something tough but cheap, steel seemed ideal except it was heavy. To keep the weight down the design used side plates braced with steel square section tube. The tube was free, being cut from some old bench legs in a skip. The side plates were made from 3mm thick steel."
— Kill Dozer website on the chassis

Tracks were used at first, these were later replaced due to the amount of current required to drive them. Kill Dozer's rear wheel drive meant the front of the robot turned in a larger arc than the back.

"Apparently tracks were used at first but these were later replaced due to friction during turning. The turning of Killdozer is worth noting as the rear wheel drive meant the front of the robot turned in a huge arc while the back went in a small arc. Most robots with 2WD have the wheels situated in the middle which means the robot turns evenly."
Oliver Steeples explains the switch from tracks to wheels[3]

The robot was powered by two 24 volt wheelchair motors, giving a top speed of 5mph, and had NCC60 24 volt controllers, supplied by 4QD[4]. The motors were obtained by a local wheelchair supplier, along with the batteries, which were 2 x 12 volt, 25 Ah dry cell.

"The motors were one of the first items to be obtained. No motors no robot, and at this stage I was still trying to decide whether to have a go at building something or not. Anyway I decided that I should try and get some wheelchair motors as they seemed to have quite a bit of power. The first local wheelchair supplier I rang said that they had an old wheelchair I could have as it was going in he skip. The cost - £10. What a bargain I thought and went to collect it before they changed there {sic} minds. After getting the chair home I discovered that the batteries (two 12 volt 25 Ah dry cells) were still in it and, after testing them with a discharger, were in good order. Two motors and two batteries for a tenner, I couldn't believe my luck. With hindsight wheelchair motors just don't have the power required for a top heavyweight. All of most powerful robots were running Bosch 750 watt motors and they are on the shopping list for next year."
— Paul Hart on obtaining the wheelchair motors[5]

Etymology[]

The name was a pun on bulldozer, a construction vehicle, which was the inspiration for the design[6].

The Team[]

Kill Dozer was entered by a team from Southampton called Raiders of the Lost Skip. The team captain was Paul Hart, a computer engineer, who drove the robot and was responsible for the design, electrics and mechanics. The other team members were Steve Scotcher, and mechanical engineer, who did the welding and mechanics, and Howard Andrews, Paul Hart's boss, who was responsible for the speed controllers and the wiring[7].

The team name came from the fact that during construction, the team sourced a lot of second hand parts for free, many of which were found in a skip, others from the teams houses or friends[8].

Qualification[]

Kill Dozer at the Series 2 rehearsals

Kill Dozer attended the Series 2 rehearsals where it was fully built, but lacking a paint job. The robot was weighed and analysed by the technical crew where it was successful in qualifying for the series.

Robot History[]

Series 2[]

"It would certainly need those hydraulics to lift the wall out of place."
— Jonathan Pearce at the start of Kill Dozer's Gauntlet run

Kill Dozer stuck on the ramp

In the Gauntlet, Kill Dozer chose the middle route, but as it drove at the wall, the spikes raised up, stopping it before it could reach the wall. As the spikes lowered, Kill Dozer pushed against the wall with its front lifter raised, knocking over the blocks easily. It was briefly lifted up the spikes, then reversed for another charge. It lowered the lifter and knocked over some more bricks, but incorrectly drove at the side of the ramp. It reversed, and drove at the ramp, but it pushed some of the bricks up the ramp as it did so, and as it got onto the ramp, it couldn't push past the bricks. Kill Dozer reversed, and as it drove back up the ramp, it tried to use its lifter to lift past the bricks, but despite lifting them a little and turning one of them over, they were still blocking its way.

"...those blocks, they've fallen unfortunately here for Kill Dozer, they're in the way still! They can lift a tonne, let's see it lift a tonne!"
— Jonathan Pearce as Kill Dozer tries to get past the blocks

It reversed down the ramp for another attempt, and Matilda and Dead Metal came over. Kill Dozer tried driving up the ramp, but in its haste to get away from Matilda, it drove along the side of the ramp, leaving it with some of its wheels hanging over the side. It tried using its lifter, but couldn't get free. The audience booed its lack of movement, and Matilda turned around and used her chainsaw to slice through the back before time ran out.

"That low ground clearance has caused it problems! Kill dozey, dozey, dozey sleepy show! And in comes Matilda! Pain on the face of the Kill Dozer team! They're worried that they might not have done enough!"
— Jonathan Pearce as Kill Dozer's run ends

Despite travelling only 5.8 metres, it surpassed Penetrator and last-placed Broot, and progressed to the Trial.

In the Tug of War Trial, Kill Dozer was the last competitor to take on Matilda

"We used spikes on the bottom of the blade to dig into the floor of the arena. Matilda didn't have a chance!"
— Paul Hart on the team's tactics in The Trial[9]

Kill Dozer uses its spike to dig into the floor in the Tug of War

Matilda pulled Kill Dozer, but Kill Dozer lowered its front lifting scoop, using the spikes to dig into the floor. Kill Dozer tried reversing, but Matilda kept pulling, so Kill Dozer dug its front spikes into the floor again. Kill Dozer managed to pull Matilda back, then dug its scoop into the floor again as Matilda tried pulling.

"The spikes were in the stage by about an inch by the end of the 30 seconds."
— Paul Hart on the team's website

Matilda reversed, then pulled again, but still couldn't move Kill Dozer at all. She kept trying, but could not pull Kill Dozer, leaving it as the only robot to survive the full 30 seconds.

Craig Charles: "I thought you were gonna actually get her into the pit at one stage!"
Paul Hart: "Yeah, unfortunately though we can't, because the rear wheels were off the ground because of the slope. We'd have had her in but the rear wheels are just off the ground!"
Craig Charles: "Ah, well. You're through to the Arena, how do you feel about that?"
Steve Scotcher: "Brilliant!"
— Post-Trial interview

In the Arena Semi-Final, Kill Dozer was drawn against Ivanhoe.

Kill Dozer lifts Ivanhoe

At the start, both competitors charged at each other, but Ivanhoe swerved to get at Kill Dozer's side. However, it missed with the lance. Ivanhoe pushed against Kill Dozer, and the two robots turned around together. Kill Dozer raised its lifter a little and pushed against Ivanhoe's side. Kill Dozer lowered the lifter, and nearly got under the side of Ivanhoe, but Ivanhoe turned around to get off the scoop. Ivanhoe got at the side of Kill Dozer and fired the axe, but Kill Dozer turned to avoid it. Ivanhoe drove around to Kill Dozer's front, but drove straight onto the scoop, allowing Kill Dozer to lift it up.

"Ooh, ooh, there's a mistake though, they've gone onto that front raising ramp, they didn't want to do that!"
— Jonathan Pearce as Kill Dozer lifts Ivanhoe

Ivanhoe pushes Kill Dozer into the PPZ

However, Kill Dozer was not able to push its opponent because its chassis was digging into the arena floor, so dropped it back to the floor because Sir Killalot was approaching[10]. Ivanhoe turned, and Kill Dozer turned and pushed against Ivanhoe's side, but drove onto the arena spikes, and as they lifted Kill Dozer up, Ivanhoe turned and used its axe, but this had no effect. Ivanhoe pushed Kill Dozer, getting it off the spike and Kill Dozer turned around to get away from Ivanhoe. Kill Dozer turned around close to the edge of the PPZ, but briefly stopped, exposing its side to Ivanhoe, and Ivanhoe pushed it into the PPZ, driving in itself.

"Both of them, very dangerously close to that PPZ, and now in! And on the spike!"
— Jonathan Pearce as Ivanhoe pushes Kill Dozer into the PPZ, but drives in itself

Sir Killalot lifts Kill Dozer

Ivanhoe pushed Kill Dozer onto an arena spike, which lifted Kill Dozer up, but because Ivanhoe was pushing against Kill Dozer's rear scoop, Ivanhoe was lifted up as well. The House Robots rushed over, with Shunt pushing Kill Dozer against Dead Metal, and getting underneath it with its plough. Sir Killalot got behind Kill Dozer, and grabbed the back with his claw and got his lance underneath Kill Dozer.

"There's Sir Killalot! Hoisting aloft Kill Dozer! They spent four months building their baby, and they can laugh? They're mad!"
— Jonathan Pearce as Sir Killalot picks up Kill Dozer, to the amusement of the Kill Dozer team

Kill Dozer is roasted over the flames

Sir Killalot used his lance and claw together to lift it up. Sir Killalot carried it over to the flame pit, and held it over the flames for a while, before carrying it over to the pit and dropping it in.

"We got caught in the PPZ by a combination of bad driving and radio interference (I know everyone blames that but it was really bad - the studio was under 11,000 volt pylons) and Killalot picked us up and held us in the flames for about 45 seconds (they cut it on the TV) before dumping us in the pit. Surprisingly there was very little damage apart from some of the thinner wires on the hydraulics controls melting. All of the motor wiring was fine and we could have continued, if we had needed to, with a few minor repairs. The rear blade got hot enough to start to melt (it was aluminium) so we would have had to take it off."
— Team Kill Dozer's version of the battle with Ivanhoe

Kill Dozer was therefore eliminated, and Ivanhoe went through to the Heat Final.

Paul Hart: "Barbecue time, eh? Barbecue!"
Craig Charles: "Barbecued Kill Dozer, and then into the pit! You looked like you could've had it for a while, I mean you lifted him up but you just couldn't push him!"
Paul Hart: "Couldn't push him, too much weight on the front."
Craig Charles: "Have you enjoyed Robot Wars?"
Paul Hart: "We have, yeah. Be back next year!"
— Post-battle interview

Results[]

KILL DOZER - RESULTS
Series 2
The Second Wars - UK Championship
Heat, Arena Semi-Final
Heat J, Gauntlet 5.8m (4th) Qualified
Heat J, Trial (Tug of War) Survived (1st) Qualified
Heat J, Semi-Final vs. Ivanhoe Lost

Wins/Losses[]

  • Wins: 0
  • Losses: 1

NOTE: Kill Dozer's successful Gauntlet and Trial runs are not included

Series Record[]

Series Kill Dozer Series Record
The First Wars Did not enter
The Second Wars Heat, Arena Semi-Final
The Third Wars Entered with Raizer Blade
The Fourth Wars Entered with Raizer Blade
The Fifth Wars Did not enter
The Sixth Wars Did not enter
The Seventh Wars Did not enter
Series 8 Did not enter
Series 9 Did not enter
Series 10 Did not enter

Trivia[]

  • During construction of Kill Dozer, Paul Hart was having problems with the ABS system on his car, so he ordered a replacement, only to realise the electric pump in it could be used to power the lifter of Kill Dozer, so used it in Kill Dozer instead[11].
  • The team originally intended to build their own speed controllers, designed around the standard speed controller/servo chips as used in smaller remote controlled cars, but they kept blowing, so they sourced speed controllers from 4QD[12].
  • Team member Howard Andrews had Jury Duty during the construction of Kill Dozer, meaning he could only help with half of the construction.[13]
  • Kill Dozer was originally intended to have tracks, but because of the amount of current required to drive them they were changed to wheels 3 days before the audition.[14]

External Links[]

References[]

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