UCLA Engineering 96G: Introduction to Engineering Design - Go Karts
Instructor: September 2021 - June 2023
Student Team Member: September 2019 - December 2019
During the first quarter of my freshman year, I took a UCLA course called Engineering 96G: Introduction to Engineering Design - Go Karts (E96G). The aim of this class was to introduce students to the engineering life cycle by having them design and build a Go Kart from scratch. At the end of the 10 week quarter, student teams would race the Go Karts and give a technical design presentation detailing their challenges and lessons learned.
Starting Fall of 2021, I also became an instructor for this course. I worked with a team of two other student instructors to develop a 10 week curriculum from scratch, plan homework materials and class logistics, and ultimately teach the class in person once a week. I also provided further assistance to students at office hours. Teaching the class was a challenging and rewarding experience, and I definitely learned a lot each time I taught the class.
Below is some of the work I did when I was a student in the class.
Overall Go Kart/Chassis Design
Due to the limited amount of time we had (10 class meetings during the quarter), most of the team’s time was focused on CAD and manufacturing. During initial brainstorming sessions, I brought up the idea of having a larger kart to improve handling while also giving the driver ample room to steer and be comfortable. This overall direction guided us throughout the CAD process, especially when it came to where to place certain components, like the seat and electronics.
I was in charge of CADing the steering system, and also assisted my team members who were new to Solidworks. When designing the chassis, I made sure we included a beam running the length of the Kart so that the weight of the driver was never fully supported by a joint but rather from the strength of the beam. This kept our chassis extremely rigid and stable when driving.
Finished Go Kart
Solidworks CAD of chassis. There is a main beam that spans the entire length of the kart.
Full CAD of the kart
Chassis almost done with assembly
Pro ackerman steering geometry. Uprights are angled outwards to vary inner and outer wheel turn angles.
Pro Ackerman Steering Geometry
When designing the steering system, I incorporated Pro Ackerman steering to achieve smoother steering and less slip when turning. Pro Ackerman steering is steering designed with a certain geometry such that the inner wheel pivots more than the outer wheel when steering the car. This allows all 4 wheels to rotate around the same point, reducing tire slip when cornering. As you can see in the pictures, the wheel uprights are slightly angled to achieve Pro Ackerman geometry. Our team was the only team to have Pro Ackerman, which helped contribute to our eventual success.
Drivetrain Gearbox Testing
During testing, we accidentally fractured both drive gearboxes when going over a bump (no suspension). This was just days before the race, so I very quickly analyzed the problems and concluded that the main issue was the way our gearbox was 3D printed. It was currently printed such that the layers could easily separate along the weak points where the motor was mounted. The entire piece could be much stronger by chancing print orientation, as well as adding and thickening some walls. I rapidly modified the gearbox CAD and reprinted it overnight. After swapping the gearboxes and retesting, we didn’t run into any issues with gearbox durability. It held up through testing and the race.
Fractured gearbox. The crack follows the 3D printed layers.
Updated gearbox. The walls are much thicker and the 3D printed layers are oriented vertically.
Race Day
During the race, the kart ran very well with very few issues. The only piece that failed was the steering block, which cracked when a driver accidentally bent the steering column too hard. With some quick duct tape and zip ties, we got it working quickly. Out of the other student teams, we placed 1st, not only because our kart was the fastest, but also because it was the only kart still working by the end of the day.
There’s nothing that duct tape and zipties can’t fix.
Steering block fresh off the printer with support material
Front view of the kart right before the race