For student balsa bridge contests
Know your contest's rules before you design your bridge.
Pick your contest and read its rules in plain words. Coming soon: a bridge that follows every one of them, and the plans to build it with hand tools.
How it works, in three steps
- 1
Pick your contest
We turn its rulebook into checks: the gap to span, the size limits, how it's loaded, the mass limit, which sticks and joints are allowed.
- 2Coming soon
Design or choose a bridge
Start from a tested design for your contest, or shape your own. Every change is checked against the rules as you go.
- 3Coming soon
Print the build pack
A full-size plan to build on, a cut list stick by stick, close-ups of every joint and the order to glue them in.
What every design will go through
Every design we show will have been through all three. Designs are coming soon.
Every rule checked on real sticks
Span, size, clear space, load, mass, stick sizes and joint rules are checked on the true-size sticks you'll cut, not an idealised line drawing.
Loaded until it breaks
A 3D simulation adds load until the bridge fails, stick by stick and joint by joint, so you see how much it held and where it gave way.
Buildable by hand
Only through-cuts you can make with a hobby knife: square or angled ends, glued between or against other sticks. No notches, no half-laps.
What it can't promise
Plain about the limits, so you know what to double-check.
Strength is simulated
The numbers come from a model of balsa and glue that hasn't yet been checked against real bridges breaking. Real sticks vary and so does gluing: treat strength as an estimate.
Judged scores aren't modelled
Design reports, looks, craftsmanship, presentations: anything the judges score is up to you.
The organizer's word is final
We read every rulebook closely. When a rule is unclear we take the reading the organizer most likely meant and show the other one. If your organizer says otherwise, they're right.