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Human-Powered Wooden Car

A life-sized, human-powered wooden car built from plywood and 2×4s — with a merged rope-and-foot steering system (and flames).

November 21, 2024
  • Mechanical Design
  • Fabrication
  • Fusion 360
  • Rapid Prototyping
  • Machine Shop

Built with Sarah Rodrigues, Maddie, Helen, and Najja for Intro to Mechanical Engineering (Ms. Selan) — the term’s second project: a life-sized, human-powered wooden vehicle, modeled in Fusion 360 and built from plywood and 2×4s under tight material limits.

From sketches to Fusion

Like the bridge, we began with sketches and then built the car in Fusion 360. Because we were working on the Fusion file on my computer, I ended up primarily responsible for the model — most of the edits and iterations ran through me, which I’m proud of.

An early design render, marked up — the push-pole, painted flames, and the steering mechanism (pink).

Working the structure out by hand — plywood over vertical 2×4s, rope holes, and a foot support.

The car modeled in Fusion 360 — chassis, seat, seat-back, wheels, and all the hardware.

Steering: rope and foot

The one thing our group debated was how to steer. We weighed Ackermann, rope, and foot steering; Maddie, Sarah, and I leaned toward foot steering, while Helen and Najja liked rope. Instead of picking one, we merged them — and it turned out to be the right call. The foot steering would have worked on its own, but the ropes gave us far more nuanced control and made the car genuinely easy to turn.

Problem-solving under constraints

  • Working across two class sections was harder than expected — we started a group chat and sent an end-of-class summary each day so everyone stayed on the same page.
  • Sharing materials: when other groups ran short on bolts, I came in after class to add extra screws so we could free ours up — which meant re-working parts we’d already built. Next time I’d plan the material budget across groups before assembly, not during.
  • Seat sizing: confusion about how much plywood we had led us to shrink every component — only to find we had plenty left over. The seat still worked (and it was actually easier to push the driver by the shoulders anyway).

The build

Sarah and I had fun giving the car personality — “KACHOW” and a lightning bolt down the spine, painted flames on the axles, and “EAT my DUST” on the seat-back. (I’m convinced the flames made it a little faster.)

The finished car, top-down — "KACHOW", a lightning bolt, painted flames, and the team's signatures.

The finished car in the shop.

The seat-back: "EAT my DUST."

I’m proudest of how much we iterated — before and during the build — and of how the merged rope-and-foot steering came together in the end.