Kaiser Tam

UTRA SUMO

When I was doing the George Brown Machining Course, one of the people that I worked with was Brendan. During the course, Brendan informed me that he was an upper-year mechanical engineering student, which was great because I wanted to transfer into mechanical engineering from materials science and engineering. Additionally, I was looking for extracurricular activities to pursue, and Brendan happened to be the Project Manager for the UofT Robotics Association (UTRA) SUMO division. And so, I gathered a couple of my friends, and decided to sign up for SUMO. Although SUMO may seem like a basic project, this project taught me a lot about collaboration, adaptability, and just having fun while doing work. The skills I learned doing UTRA SUMO can be directly applied to future roles in the mechatronics industry. I hope that this page acts as a snapshot for my progress with designing for 3D printing, Arduino, and teamwork!

SUMO 2023-2024

The first thing our team did was research. This included looking at professional SUMO matches to see what strategies different teams used, carefully analyzing the rules and constraints for our robot, and looking at Fusion360 tutorials to make CADing the SUMO robot easier. This allowed us to create some specifications for our robot.

Taking dimensions for all of the parts. This was great for blocking out the parts that needed to go into the robot, such as motors, wheels, batteries, and various hardware components.
Wheel measurements. One of the challenges that we had with SUMO 2024 was deciding whether to use thick or thin wheels. Thin wheels took up less space and allowed the robot to be more agile, while thick wheels provided more traction but were heavier and made the robot slower. Ultimately, we ended up using thick wheels to prevent our robot from being pushed off the platform.
Useful resources and constraints. Since our team was working during our first year at UofT, we followed a bit of a brief “ESP” document. Obviously, this is not a properly formatted document, but it did provide our team with necessary information to design the robot.
Rough ideas in my engineering notebook for initial designs of the robot. At this time, I had very little knowledge of designing for 3D printing, which meant that a lot of values I used such as wall thickness were way too large. Furthermore, I did not realize I could just use infill for holes for the ultrasonic sensors.

Once we CADed the robot in Fusion360 and Brendan 3D printed the robot at the MyFab facility, we instantly ran into a couple issues. First of all, I may or may not have forgotten to add eye holes for the robot. Another issue that we faced is that we had to solder the motors SO many times because the wires snapped off so many times. Finally, we were having a lot of difficulties with getting the code to run consistently because there was a lot of variance between tests. Even if we did not change anything in the code, the robot would perform different. But it was alright, as we had a finished robot the day before the competition!

The wires snapped off after soldering SO. MANY. TIMES. But at the end of the day, it was alright, as we still managed to create a working robot!
All the parts that we were allowed to use, and Timbits! Making sure everything fit inside the allowed space was a fun challenge to have.

And then came the competition day, the day of the SUMO in-house tournament. During the competition, we ended up falling into the lower bracket in our first match. However, we then proceeded to win our next 5 matches, and we ended up in the final. Our strategy was pretty simple for the tournament: run in circles, let the enemy robot get too close to the edge, and then push the enemy robot out of the ring! Overall, our team had a blast competing in our in-house tournament!

The final robot, ready to go! We drew a smile to add to the ultrasonic sensor!
The lower bracket bracket, where we played pretty well. Although we eventually lost in the final, we had a blast!
Overall, we had an amazing time (I am in the back, 2nd from left)! If only we could make improvements to our robot…
SUMO 2024-2025

During the 2024-2025 year, I decided to do SUMO again. Sure, it is a bit more of a beginner-friendly activity, but it is also so fun. Justin and I stayed on our team, and we wanted to be more of advisors to our team, letting the newer teammates make the major decisions. We did a lot of reflecting on what worked well and what went wrong. Additionally, we had to adjust to a slightly different ruleset for this year.

General changes we wanted to make to the robot. Our previous design had poor space efficiency, and the sensors were way too high up to see other robots.
More fixes and specific action items that we wanted to improve on during the year. If we improved in these aspects, we would have been happy with our progress.
Designing with the new rules in mind meant that we could add in new features, and create a more unique design compared to the previous design.

After finalizing the design for the robot for the 2024-2025 school year, our next step was to design the vehicle using Solidworks. While I did not myself CAD the vehicle, I did provide my team with as much insight as I could on how to design for 3D printing. Having CADed our robot for the 2023-2024 season, I wanted to help my teammates learn as much as they could about designing for 3D printing as possible. During the CAD process, I advised my team about things such as elephant’s foot to ensure that our 3D print would turn out better than it did last year. One issue that we ran into was just that we could not find linear actuators for our design, and our design would not fit in the required 10×10 area. Therefore, we had to make some changes to our design. However, I think that the design turned out quite well.

Our final CAD model for SUMO 2024-2025. For this model, we decided to have our sensors closer to the bottom of the robot to ensure that no matter how tall an opponent’s robot is, we can still detect their robot. Despite having less space for components due to this year’s regulations, this robot manages to fit the same components into its frame, which makes it more space-efficient and hopefully, better offensively.
Testing out what the print would look like using Bambu Slicer. Making sure that the print would work well and limited work would need to be done afterwards was important in validating our design; it does not matter how good our design is in theory if it would not print out a desirable robot.
The final robot printed out. In this photo, you can see that the wheels stick out of the robot as they are too wide. The actual wheels we used in competition are thinner so that they do not stick out of the robot. This reduces the likelihood of a team pushing us outside of the ring from the side of the robot.
Inside the robot. Chris did a great job with programming the robot in C++ so that the robot worked as intended. He also gave us a lot of material to reference for when we were at competition, in case he was not there when the robot broke.