MIG Welding · Metal Fabrication · Drivetrain · Brakes & Steering
Lemon the Train was a drivable, train-styled vehicle built by FLiNT, a student engineering build club — I owned two of the project’s four work tracks by myself, taking the vehicle’s mechanics from a non-running frame to a working drivetrain with a completed straight axle swap.
Role: Mechanics and metalwork, solo | Team: FLiNT, split across mechanics, metalwork, woodwork, and painting | Timeframe: FLiNT membership, October 2023 – April 2024
The problem#
The club had a vehicle frame and an idea of what it should become, but nothing underneath it worked well enough to drive: the engine and drivetrain, brakes, and steering all needed to be retrofitted before any of the visible train-styling work meant anything. Nobody on the team was doing the mechanical or metal fabrication work.
What I built#
I took both of those tracks on alone. On mechanics, I handled the engine swap, the brakes, and the steering, and replaced the rear end with a straight axle — that swap was finished and functioning. On metalwork, I did all of the cutting, grinding, and welding the build needed. I taught myself MIG welding for this project, starting from no welding experience at all, because otherwise the fabrication wasn’t going to get done. The woodwork (panels, windows, doors) and the painting and visual design were other members’ tracks, not mine.
Results#
- Owned 2 of the project’s 4 work tracks solo, with no other member contributing meaningfully to either.
- Completed a straight axle swap that worked, along with engine, brake, and steering retrofits.
- Went from zero welding experience to doing all of the build’s MIG welding, self-taught during the project.
- Brought the vehicle to near-complete: by the team’s own status review, only brakes, engine wiring, final cosmetics, and street-legal clearance remained.
What happened to it#
The train never went street legal. The team didn’t get clearance for the use it was built for, and the project was scrapped short of the finish line. The motor and drivetrain were salvaged and went on to power the first prototype of the Modular All-Terrain Rescue Vehicle (MARV) — so the mechanical work here outlived the vehicle it was done on. The welding I taught myself on this build is the same skill I later taught to 16 students on that project.