Robot Wars: a guide to stopping your robot catching fire

After last week's Robot Wars arena blaze, we chat to cool expert Dr Chris Aldham about how to keep a robot from bursting into flames...

Between flamethrowers and fire pits, in the Arena of Destruction it’s all too easy for robots and roboteers to get a little hot under the collar. While most viewers would be happy to watch the new series and appreciate it for little more than the fiery destruction it is, we had to take it that step further and unleash our inner geek.

That’s why we took a look under the hood of this year’s competitors to find out how they’ve tried – and in some cases failed – to stop their machines bursting into flames.

To lead us on this journey, we spoke to Dr Chris Aldham, a thermal management expert from simulation software firm 6SigmaET. With over thirty years’ experience in engineering and thermal management, Chris knows how to keep things cool…

Given the Robot Wars arena is full of spikes, flippers and circular saws, is overheating really the biggest concern?

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Although flamethrowers aren’t making much of an appearance this series, the arena flame pit will still be reaching around 1600ºC. Given that most standard electronic components don’t like operating at anything much above 150ºC, it’s safe to say that a trip to the flames is a serious concern for most contestants.

That said, overheating isn’t just about flamethrowers and fire pits. All of the machines competing in this year’s series use powerful weapons, and their control electronics will have to run pretty hot. At the same time, plastering these devices in bulletproof armour isn’t exactly going to help with airflow and ventilation.

Many of the robots in the new series are constructed from HARDOX, which makes fantastic armour (being both stronger and lighter than titanium), but its thermal conductivity is hardly ideal. Ironically, as the robots get cut up and have holes punched in them, this could actually help the airflow inside that armour – keeping the components cool and stopping them from cutting out before they’ve even started.

What are this year’s roboteers doing to keep their machines cool?

This year’s contestants have used a massive array of different methods to keep their robots cool – some professional and others, well… less professional.

At the top end of the scale are team PP3D, who used a professional LeakHeat thermal imaging camera to maximise the performance of their design. As seen on Episode 4, PP3D were able to analyse their robot for potential hotspots, ultimately identifying an issue with the weapons belt as well as a motor that had burnt out inside the machine.

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While that’s a great solution, most hobbyist engineers don’t have immediate access to professional thermal imaging tools or simulation software.

Team Carbide are a great example of a group of contestants who went out of their way to find a thermal workaround on a budget. Having designed and built their machine, Team Carbide went online and bought a set of NOMEX formula 1 racing suits. Cutting up these suits, Carbide used the individual shreds to flameproof the insides of their robot, helping it survive the flame pit and securing their place in the series finals.

But it’s not just heat that’s a problem in the Robot Wars arena – all temperatures can have a negative impact on the effectiveness of these machines. Right back in episode 1 we saw the first example of this, with the mighty Thor quickly losing control of its axe apparently because the BBC studio was too cold for it to function effectively.

What advice can you give to future contestants to help them survive in the next series?

First, they should think about thermal management from the outset. It’s all too easy to get wrapped up in creating a destructive weapon and a cool chassis, but if your robot cuts out due to some unseen thermal issue you will have lost the battle before you’ve even begun.

Second, consider the airflow inside your robot and how the armour you select is likely to impede that airflow. If you have access to thermal simulation software to test this out, even better. If not, perhaps consider developing some basic prototypes to try on top of a barbecue.

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My final piece of advice is something that any Diotoir fan will tell you –  don’t make your robot out of felt.

Dr Chris Aldham, thank you very much!