How to run a robot wars competition* (*when only 4 robots turn up**)

cover photo credit: Jefferson Sanchez

(**and only three actually move)

So, as you may (or may not) know, myself, and a few of my coursemates, have been setting up a robot wars competition in our uni. (If you want a little background, have a quick read through of the previous post on the matter here). So, anyhow; this time we actually managed to run it, on the 26th of February (yeah, this post is a little late; I’ve been busy. and lazy). Initially, we had 7 teams; this kind of dropped off a bit, with various teams dropping out for various reasons, until there were 4:

Ethel (the unready)


  • Weapons:
    • 102W BLDC eggbeater
    • Wedge with servo lifter
  • Drive: 2x ebay DC gearmotors (1:48, i think)
  • Construction: 
    • 3mm laser cut acrylic
    • 3d printed PLA
  • Final position: 1st

As you’d know from the sporadic updates, this one’s mine; Hastily patched together the night before, and held together with a large quantity of sellotape and bad language, it spent most of the contest in pieces, due to a bit of bad design on the fit of the battery (IE I entirely forgot that batteries have cables), coupled with a bad connection on one of the motor units. In the first battle (against one-punch robot) the rear egg-beater got entirely obliterated, meaning it got hastily re-configured as a basic wedge for the rest of the competition. Nevertheless (and I don’t quite understand how) it managed to come out victorious overall; feel slightly guilty about that. Anyhow, I’ll do a full post-mortem in another post.



Photo credit: Jefferson Sanchez
  • Weapons:
    • Nothing, bar the ability to keep working in the face of punishment
  • Drive: 2x ebay DC gearmotors (1:48, i think)
  • Construction:
    • Plastic box
    • Piece of wood
  • Final position: 2nd

This one was Julian’s robot; My housemate, and co-organizer of the competition. He took the probably more sensible KISS option on his robot; basic pusher-bot, made by bolting some motors on to the outside of a screw container, with a bit of wooden armour up front. While not the most offensive ‘bot, it took all the punishment going, and just never stopped running. it’s main issue was a lack of grip, which gave me the edge against it, since I could push it around quite easily. He came second overall, and won the recycling prize (WD40 to keep things moving that should be, and electrical tape to stop things moving that shouldn’t be)

One Punch Robot


Photo credit: Jefferson Sanchez
  • Weapons:
    • A rather scary 102W 16mm plywood spinner
  • Drive: 2x ebay DC gearmotors (1:48, i think)
  • Construction:
    • Polycarbonate
    • Plywood
  • Final position: 3nd


The only team entry, this one was, to be frank, genuinely scary; the spinner mounted on the front is made out of 16mm plywood, and is strapped on to a 102W 1100KV BLDC motor, on a prop mount which had a bit of a tendency to break loose…

Apart from the whole spinner-breaking-free-and-going-flying issue, this robot was pretty reliable too, and was a definite crowd-pleaser, being responsible for basically all of the carnage (namely, the decimalisation of my weapon) of the day. It’s main issue, apart from the obvious spinner problem, was that it had a bit of a tendency to keel over backwards, immobilizing it; this left it with an overall third place, but they did take home the crowd-pleaser award of feather boas and disco balls.

Sir, Scissor


  • Weapons:
    • 2x BLDC spinners
  • Drive: 2x continuous rotation servos
  • Construction:
    • 6mm acrylic
    • 3d printed PLA
  • Final position: DNF


Neil’s entry to the competition, this ‘bot unfortunately was suffering from technical issues during the competition, so never really got the chance to fight. An invertible dual contra-rotating spinner, with continuous-rotation servo-driven wheels, this had potential, but issues with the ESCs meant that the receiver wasn’t getting enough power to drive the servos. He ended up parting out a lot of it to keep other robots running; One-punch munched through the prop adapters, and he lent me one of his lobotomized ESCs to power my receiver when my weapon bit the dust. Better luck next time, Neil.


Audience-wise, around 30 people turned up, which was enough to satisfy the IET’s requirements for supporting the event. While this event was slightly under-represented in the robot department, people seemed to have a good time, so all going well we should be able to run it again sometime soon.

Anyhow, I’ll leave you with the video of the last fight of the day: We had enough kit to have a three-way fight with the running robots, so that’s what we did. Neil’s running my bot here, hence why I’ve got the video; Jefferson did most of the photography/videography for this competition (hence why he’s got credit on a lot of the pics here)


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