- Timeframe
- 2024, five-week build
- Team
- Sole designer and fabricator, Averroes High School
- Role
- Designer and fabricator
- Scope
- Full vehicle build from recycled material: chassis, steering, and powertrain
- Constraints
- Under $500 budget, five-week deadline
- Tools
- Fusion 360, MIG welding
- Status
- Held a 180 lb rider through cruising and drifting loads with minimal to no chassis flex, ran a 40 mph top speed
Objective
The objective was to design and build a functioning trike within a five-week deadline, staying under a $500 budget. Beyond that, the chassis had to hold my own body weight, 170-180 pounds at the time, without any major flex, and I wanted a real model to build from rather than working off sketches. So, I modeled the chassis in Fusion 360 to have something to reference while welding.
I also decided to teach myself MIG welding from scratch and weld together the entire chassis. My goal was to have the trike fully running by the end of the five-week program so I could present it at a design symposium.
Approach
Modeled the chassis in Fusion 360, then built it out of 1.75 mm wall steel square tubing, teaching myself MIG welding from scratch as I went. I had to make some design adjustments on the fly, and the welds were not the prettiest, but the chassis came together solid.
The powertrain needed more work than expected. The Predator engine had seized, and getting it running again meant working through a clogged carburetor, a bad spark plug, and the seized flywheel. For the drivetrain, I mated a go-kart rear axle to a bicycle front fork and tuned the head angle for steering stability at working speed.
Result
The trike came together and ran great. It held a 180 lb rider through lateral drifting loads with minimal to no chassis flex, and the rebuilt engine and corrected steering geometry got it to a 40 mph top speed.
Unfortunately, I ran over on both time and budget. The wheels I had originally sourced did not fit the rear axle, so I had to order a replacement set that pushed the total ~$100 past the $500 target and beyond the five-week deadline. Regardless, this project was a success.
