Self-built GoKart
Year
2023-2024
Involved
Mechanical Engineering
Design
Credits
James, Kilian, Denis
Idea
There wasn't really much thought: me and my friend were sat together in class on a warm afternoon. We were pretty close to the summer holidays and thought about things we could do. And then suddenly: "Wouldn't it be cool if we built a gokart?"
So, we just started, without any prior experience or exact plan on how we were going to do it. I guess we were young and naive, we were only 15.
Eventually, we thought things out a little bit more and invited another to friend to join the project, so that we could split costs and make it more realistic. And then we got to work!
Process
We started off by buying square steel and an angle grinder. Then we spent the first week planning, ordering parts and putting together the chassis in my friend's grandfather's garage. Since we wanted to maximize cost efficiency, we assembled some used parts. We bought tyres from eBay, used my disassembled old desk chair and went to a car parts store to get a used steering wheel. But (fun fact) when the sales person at the store heard about our story and our age, he gave us the steering wheel free of charge, praising us for our atypical passion for such a project.
Soon, we had all the parts we needed and got properly started.
The Axis
First we built together the axis. We used self-constructed steel brackets for the brakes, brake disk and the gear. Then attached these and their components to axis. The axis as a whole is connected to chassis via two big bearing housings. We were aware that this could cause minor issues when turning the kart at low speeds, since the outer wheel is supposed to spin faster in turns than the inner wheel.
However, we couldn't find any differentials for the wheels and also dreaded cutting the axis in half since the brakes would then only work on one wheel. Fortunately, this issue later turned out to be negligible. Soon after we mounted the 6,5 horsepower four-stroke engine and connected it with a motorbike chain to the axis. To pull the acceleration ruder back into idle, we attached a Bowden cable, that's being pulled back by a spring. And finally we added some pedals and connected further Bowden cables to the brake and the engine.
The Steering Mechanics
The steering mechanics were pretty straight-forward: Just connected the steering wheel to a steel pipe that turns and moves a threaded rod from side to side and steers the left wheel. The right wheel was simply connected to left wheel with another threaded rod, but from behind the centre of the wheel, which turns both wheels synchronously.
Eventually the kart was complete and we could properly test it for the first time in months. And we were blown away by how incredibly fast the kart could drive: It could reach an astonishing 75km/h (46mph) on flat roads!
