Markforged at BattleBots: Critical System Improvements in the Heat of Battle

BattleBots. It’s exactly what it sounds like. 250lb remote-controlled robots battle it out in a fight to the death. As part of a team on the show, we used Markforged printers all throughout the design, build, and repair process of the 2018 and 2019 seasons to create Valkyrie: a sleek, fighter-jet like robot with a nasty 65lb undercutter blade. For all the ways our printers helped, there was one way that Markforged machines were really able to help out during competition. They didn’t just fix robots, they made them better.

What many people don’t know is that all of BattleBots is filmed over the course of two weeks in April. When we shipped ourselves and Valkyrie across the country to compete on BattleBots this year, we had no idea what the season would be like or who we would be fighting. The only thing within our control is what we can do ourselves: build a good robot and be prepared to fix it. We wanted to come prepared. We knew we needed tools that could help us rapidly iterate through modifications that could improve how Valkyrie performed in the BattleBox. That’s why we brought four Markforged 3D printers to the filming location.

Every fight, you learn something new about how the components in your robot behave when pushed to their limit, and you usually have about a day or two between fights. It’s important to not only be prepared to replace parts of the bot if damaged, but improve on them — and quickly. One of our design choices for BattleBots was to design and maintenance Valkyrie NASCAR-style. Almost any part of the robot can be quickly removed and replaced with a few bolts, and the whole robot can go from a pile of parts to ready-to-fight in under an hour.

One of our biggest assets as a team is the ability to very quickly debug issues with the robot and come up with solutions on how to fix them. A problem we faced this year was rear-end motor support. Our drive motors are face-mounted to their gearboxes, leaving the rear-end unsupported. Like most design decisions in BattleBots, looking back, we weren’t sure how much of a problem it would be, but it would have been smarter to think about it earlier. Whenever Valkyrie took a big hit, our baseplate would flex, bump the drive motor, and dislodge something inside to render it useless for the remainder of a match. This happened during our Episode 1 fight against Hypershock — and it was that failure mode that beached Valkyrie upside-down by the end of the fight.

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During the qualification rounds, we fight roughly every other day. We won our second fight against Ragnarok with a one-hit KO, so we took the time we had to improve Valkyrie for our next fight against a terrifying vertical spinner: Monsoon. Monsoon, like Hypershock, is a vertical spinner that can do some serious damage. We didn’t want to end up stranded again, so we sought out to fix the drive motor problem. We needed something that met the following requirements:

• Low-profile: It couldn’t get in the way of any other components in the robot (almost all of the space inside Valkyrie is taken up by batteries and electronics)
• Lightweight: Valkyrie can’t go above 250lb weight limit, so any solution couldn’t weigh too much.
• Shock absorbing: It needs to handle the immense shock and loading conditions that come naturally to BattleBots.
• Conformal: The supports should ideally distribute the force from shock load across a large surface area to reduce its impact on our components.
• Quick turnaround: With only a day or so to iterate, we wanted something that we could make and install before our next fight, on both our main frame and our spare frame.
• Long-term solution: Quick fixes are undesirable in BattleBots because you have to keep making them. We wanted something to last the rest of the competition.
  

This is why we turned to Markforged for a durable, custom, lightweight, and quick-turnaround solution. In less than two hours, we designed the conformal mount, printed a pair, and installed it on Valkyrie. The mount itself sits between the motor and the frame, and is laced with continuous Kevlar® reinforcement to handle the shock of any mid-battle forces. We drilled a countersunk hole in the frame and designed a locating feature in the part to line up the support when it got installed on the robot. Problem solved. It was that easy. We took them into battle for a test run.

And they worked great! Our drivetrain performed flawlessly in the fight against Monsoon, and the fix also vastly improved the reliability of our drivetrain long-term. The really neat thing about this was that we weren’t the only team that came to this solution. Many of the teams had similar motor-support issues, with similar symptoms, and they turned to the on-site Markforged 3D printers to make improvements. Here are a few examples:

On a larger scale, the printers on-site at BattleBots did more than fix robots: they made them better. There were many more examples that our team and many of the other teams had during the event that both fixed and enhanced their robots because of the printers on-site. It’s rare that robots improve over the course of an event, but in this case the printers were able to increase the performance of many bots on the show, making for better robots, better fights, and an awesome season of BattleBots! You can catch episodes of BattleBots on Fridays at 8PM on the Discovery Channel.