Battlebots Team Retrograde

Flamethower Design Engineer: June 2021 - September 2021

Battlebots is a competition where two robots in the same weight class fight head on to see who can destroy, or knock-out the other robot first. It’s an incredibly exciting sport that has been around for a while and requires human driver skill and an incredible amount of engineering to win. Robots come in all shapes and sizes, but my team and I were specifically focused on the 250 lb weight class for the Battlebots TV show on Discovery Channel. Retrograde is a very unique robot as it has two main weapons: a powerful lifter in the front, and an undercutting spinner in the rear. This allows for lots of different strategic options depending on our opponent.

My job specifically was to design and build the robot’s flamethrower weapon from scratch. Due to confidentiality reasons, I am limited in how much information I can share here, but the main steps I took to create the flamethrower were:

1. Research and Define

   1. This was the first time I and anyone else on the team had ever made a flamethrower. I spent a large portion of my time understanding the basics of how flamethrowers work, types of fuel, controls, etc. I also looked at previous flamethrower designs to see how they were implemented. Based off my research, I defined certain components that were required, and made sure to make note of design rules from the competition as well.

2. Initial Testing and Prototyping

   1. Just to get a rough idea of how to build a flamethrower, we purchased off-the-shelf components from stores like Home Depot, Harbor Freight, etc. to put together a working prototyping with the intent of gaining as many learnings as possible.

3. Design

   1. After learning everything we could from research and prototyping, we went into the actual design which involved CAD work in Fusion 360 and a lot of time spent looking for the ideal components (e.g. solenoids, igniters, batteries) to fit in our design.

4. Build

   1. We worked with sponsors to lasercut and bend the structural components. After all components had arrived, the build and assembly was relatively straightforward as we had designed the system to be very simple.

5. Test and Validate

   1. The design didn’t work perfectly the first time, so we spent a good amount of time tweaking small parameters independently to improve ignition and flame length. This process involved a lot of iteration and trial and error to get it to a point where we were satisfied.

6. Compete

   1. This is the fun part! I can’t share many details about the competition as it hasn’t aired on TV yet, but I can assure you it was very cool.

Overall, developing the flamethrower was a very exciting and insightful learning experience. I love being thrown into projects where I don’t know exactly what the right thing to do is, as the fun part is finding your way through the challenges and learning an incredible amount while doing so.