Odyssey of the Mind – Balsa building secrets

Geek Culture

No problem group at Odyssey of the Mind touches people as deeply as the Structure or Building problem — as our Geek Dad Commentors remind us. We spent this morning among the young builders picking up on secrets that have been passed down through dynasties of balsa builders.


This year’s problem is called Out of the Box Balsa:

The team’s problem is to design, build, and test a structure made of balsa wood and glue that will balance and support weights. The team is allowed to use materials other than balsa wood and glue to assemble the parts of the structure. The structure will be designed to fit completely inside a box that is smaller than the assembled structure. When competition time begins, the team will remove the parts and assembly materials from the box, creatively assemble its structure, and test it by placing weights onto it.
Cost limit: $125 USD.

There are some interesting aspects to this problem if you think out of the box. One team did today and their structure which weighed in at less than 18 grams held 1050 pounds! Even so that team may not be the winner; a team from Arkansas was rumored (only one source and he from Arkansas) to have held 1452 pounds at their state competition. That Arkansas team will be up tomorrow.

The inside the box balsa tips are:

  • Pick your wood carefully. Inspect the grain. Look for cracks, dents and imperfections.
  • Carefully apply your glue and trim any you don’t need.
  • Bake your balsa. Weigh in is 2 hours before the performance and moisture is unneeded weight. We saw teams take their structures hot out of a toaster oven and direct to the weigh in.
  • Level your structure. The best builders use levels and/or plates of glass to check that the weight will be evenly distributed.
  • Deploy your team members wisely. One coach told me that her team formed a fire brigade from the weights to the structure in such a way that the member putting on the weight and most others didn’t even move their feet. This gave them plenty of time to be careful when placing the weights.
  • Four legs are better than three. I would have thought that a triangular prism was stronger than a square prism, but the coaches and builders I talked to said no, you need the four legs or you’ll be off kilter for sure.
  • Think outside the box. The structure that held over 1000 pounds was actually three square prisms, joined by some very light string, placed broadly apart spreading the pressure out nicely.
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