# Toothpicks designs.

## With lots of toothpicks and time, I made some geometrical figures using wooden toothpicks. (3/13/2006)

I may say: "I had nothing to do, so I started to do this", but that is not true. I started to do this to learn more about some structures and "failure points".

First, I designed three basic figures using toothpicks and hot glue. I used a glue gun instead of instant glue. Instant glue is stronger but is messy and have zero flexibility. Is tricky to make the designs but after a while is easy.

I tried only three basic geometric shapes: Cube, Octahedron and Tetrahedron. If you have no idea wich one is the Tetrahedron, is the pyramidal one. The Octahedron is one that looks like two pyramids together. If you have no idea wich one is the cube, you are lost.

Definitely, the cube is weak, less than half pound was enough to break it. Cubes are not the best shape to build.

The Octahedron and the Tetrahedron are really strong shapes. I used about seven pounds to break these figures. The Tetrahedron is the strongest one.

As you can see on the photo, the tetrahedron had one failure point. The octahedron have two failure points. I call "failure point" the junction or place where the structure fails and colapse. I'm not a mechanical engineer, so, if I'm wrong, let me know.

To give you an idea how strong are this shapes (based on triangles), let me show you a picture of my notebook computer over the octahedron. My old notebook have a weight approximately five pounds and half (more than two kilograms).

At the beginning, I was afraid to break my computer if the toothpicks or the junction breaks apart, but fortunately, nothing happen and the structure was able to hold the notebook.

If you notice it, the cube and the octahedron have twelve toothpicks, but the strength is not defined by number of toothpicks, the strength is define by the shape. All triangle-based shapes are really strong.

After this test, I will build some structures with toothpicks, specially bridges. Some schools have contests to build bridges using toothpicks, these bridges looks really cool and some of them can hold many times the weight of the bridge. You can find lots of web pages and links about the wooden bridges and toothpick bridges.

I wonder if I have to use my computer to test these bridges. I may need to buy some bricks.

< Super Simple Sun Tracker. | Homepage science Index |
Toothpicks with yummy designs.> |