“We’re going to need guns, lots of guns” was the famous line from “The Matrix” films and when it comes to weapons, the design of Storm 2 is exactly the same.
The design process for Storm 2 borrowed straight out of IT architecture best practice, everything from ensuring we minimised single points of failure (did you know that Storm 2 can lose all 4 of its drive chains and still keep running?). Also, just like any good IT architecture, the design is modular – meaning that Storm 2 can make use of multiple weapons.
When Storm 2 first entered Robot Wars there was no rule that said you needed a weapon – and as a team we quickly realised that a weapon was actually surplus to winning, however that all changed when Series 7 of Robot Wars was filmed and we were told that without a weapon, Storm 2 wouldn’t be allowed to compete – even though it had just won the ‘New Blood’ championship on Robot Wars Extreme, gaining us automatic seeding into the new series.
The robot has three main weapons:
- Four Bar Linkage ‘lifter’. This is a high performance electric lifter. Often in fighting robots people will use CO2 (Carbon Dioxide) to run weapons systems using pneumatics, but the downside of these is they are heavy, have limited gas on board and require expertise that the team didn’t have coming in to the design. The four bar lifter was designed by John Reid of the Terrorhurz team in the UK (and also from BETA in the US) and had to overcome some huge design challenges. With the change in weaponry rules, we had to redesign the whole inside of the robot. We were determined that we would come back to the next series not only with a weapon, but with even more armour than before. The four bar lifter is therefore manufactured out of CNC 7075T aluminium – aerospace grade and expensive and hard to work with. It uses a 4hp motor to drive the lifting arm which can move from down to up in about 0.3 seconds with total precision thanks to a potentiometer which provides feedback to the brains of the robot and ensures that the arm doesn’t move too far – there are no physical end stops!When would we use it? The downside with the arm is that Storm 2 can’t self-right, and relatively speaking it’s quite fragile. The team pick the arm when they have fights where turning a robot over is key, but they’re not left in a bad place if they get turned over. For example, they might fit it when fighting a robot with a heavy spinning disk as a weapon.The arm was decisive in Series 7 when it helped them win the World Championship, and also helped in the UK Championship by turning Tornado over. Once inverted their scoop couldn’t get underneath our machine, and it allowed the team to control the fight.
- Forward Firing Lifter. This is in fact a different configuration of the Four Bar lifter mentioned before. This one is designed for fights where Storm 2 is up against something that can easily turn it over. It has two purposes, If they are a flipper then they have to waste gas to self-right and get back on their feet. In addition, should Storm 2 get turned over, with little momentum Storm 2 can use this weapon to self-right. This weapon is effective when combined with the front scoop of Storm 2, which could literally strip paint off a floor it sits so low, enabling the machine to get in underneath someone and turn them over. Getting someone off the ground is always critical to winning – it doesn’t matter what weapon you have, if your feet aren’t on the ground, you can’t deploy it !As we have in effect an unlimited power supply on board in the form of electricity, and a flipper only has limited CO2 – this should eventually allow us to win a match as we simply run the opponent out of CO2…. That’s assuming, of course, that we don’t get thrown out of the arena!
- Vertical Spinning Disk. One of the weapons that we wanted to create was something that could do some real damage and that changed the visual shape of Storm 2. One of the things we really focused on from the start was keeping that visual look of the robot – going to huge lengths to avoid changing the chassis, and in fact the chassis that you see competing today is still the same chassis that we build for Robot Wars Extreme: New Blood back in 2003/4. The vertical spinning weapon was a collaboration of design work between ourselves and Ed Wallace, a talented engineer with whom we work. We had a set weight, and picked the components that we needed to ensure that it was ‘plug and play’ into the robot. It uses the speed controller that usually runs the arm to power up the spinning disk, and has a separate telemetry system that gives live feedback on current draw and disk RPM. The disk motor is designed to work at 24v, but using that live telemetry feed – if we realise that we’re not causing enough damage with it, we can unleash the full 42v that Storm 2 carries on board. Energy is a square law with speed, so doubling the voltage will quadruple the energy that the disk hits with. It’s only through having access to real-time data off the robot that means we can see if we’re within the operating temperature range to allow us to deliver the full 42v without risk. Otherwise the only way we find out we’re over-stressing the robot might be when smoke starts to come out!
Coming next time, we’ll explore why software plays such a vital role in running Storm 2, from the software used to design it, to the software on-board the robot itself. If you can’t wait till then, check out last week’s blog, looking at the materials used in Storm 2 and how it is constructed.