MY 29 Toothpick Structure!



In our class, the assignment was to build a structure out of 29 toothpicks that could hold at least ten pounds. We learned how compression and tension worked and how to solve a problem in design and construction. These structures were built on a 7x7 piece of cardboard. Each of us worked with a partner and built several designs.

         There were many difficult steps involved in the process of construction. Before we started building, Sheridan and I wrote an analysis of the first design. Next, we drew the layout on the cardboard. Then, we glued the toothpicks together in a tepee fashion. Finally, we tested the structure with dead weights and it broke after holding 115 pounds. The reason it collapsed was that tension and compression snapped most of the toothpicks at the same time. We decided to make the next structure stronger by placing the toothpicks differently for better support.

This was our first structure.


We built our second structure a few days later. Even though we kept our basic design of the tepees, we changed the placement of the toothpicks. This time we arranged them as if a dice had rolled a five. Our new design provided more support for the weight than our previous structure. It held 197 pounds, but we needed to make a few minor adjustments to strengthen it.

This was our second structure.


Our third structure was harder to build and took more time. First, we glued two toothpicks together. Instead of using only twenty-nine single toothpicks, we had fourteen doubled toothpicks and a single one. This strengthened our structure and it held 300 1\2 pounds without breaking. Though there were heavier weights in the end, it was unsafe to put more weight on the structure. A few days later, we retested the same structure. It held a total of 402 pounds because we put heavier weights on the bottom.

This was our third structure.


After building several structures out of twenty-nine toothpicks, I learned a great deal about tension and compression. If tension has pulled apart the structure, the toothpicks need to be arranged in a different way. However, when compression has pressed the structure together, it needs to be reinforced. I have also learned that it is very important to plan carefully first and not rush. I never knew that twenty-nine toothpicks could hold 402 pounds!!!