Egg Lander 2

Egg Lander 2

With my new group, we have decided to build an hourglass shaped egg lander, with straws connecting each end to form a rectangular prism. It is composed of two identical trapezoidal pyramids with the egg secured in the middle between the two pyramids.

We thought that the hourglass shape was a good idea because it was symmetrical. Once again, we tried to emphasise flexibility of the structure, but we didn't have enough straws left to make a bouncy base. However, we did try to make the surface area of the pyramid greater so it would absorb more impact. The egg holder was the good old straws interlocking each other to hold it in place. The leftover straws were not enough to make bouncy paddings of the shape # but we did use them to connect each vertex of the pyramids to another.

However, one thing we neglected again was aerodynamics. Our structure was already pretty heavy, with 24 straws and a decent amount of tape, and it was in no way aerodynamic. Our structure also failed to keep a perfect shape. As you can see from the above picture, the top pyramid's square was bent compared to the bottom pyramid's square.

I don't have a picture of our egg lander after it's dropped, but to put it nicely the egg broke again. One group that did a similar design as ours had successfully protected the egg during the drop. They had a prism with straws holding the egg in the middle too, but they attached the straws from the edges, not from the vertex, where support was apparently weak. In my group's defence  I can say that our design was pretty good except we neglected aerodynamics and underestimated the structure of the egg holding mechanism. If in the future I ever build another egg lander, I would follow Mr. Chung's advice by making a sling shape egg lander since it uses very little straws and is also aerodynamic.

Egg Lander

Egg Lander

Hey guys. Welcome to my boring blog of what happened to an egg lander we built in class.

The materials we were allowed to use were twenty straws, a sheet of newspaper, and two table lengths of tape.

Within our group, we have decided to build a tetrahedron with the egg in the middle. Now I know this may sound a little crazy. Tetrahedron? What's that going to do? Well look, we didn't know what was going to happen, but there are reasons for our insanity.

1. We have learned in physics that triangle is the strongest shape. A triangular structure (the tetrahedron) when subject to a strong force will only collapse because of material fatigue and not of geometric distortion. It is really hard for a triangular structure to cave in on itself, but relatively easy for a square/rectangle to do so.

2. The tetrahedron also uses less straws to construct.

3. The tetrahedron is symmetrical which is important for a rigid structure. Mr. Chung said that "Do not assume the egg lander will drop a certain way". Since the egg is strapped and suspended in the middle of the tetrahedron, it doesn't matter which side it is dropped on, because the egg would still be smack in the middle.

Our logic in using triangles were correct. However, we didn't do enough to protect the egg. As we will soon witness, the structure survived the impact perfectly, but the egg...not so much.

Woopsies. We kind of knew beforehand that the egg wasn't going to survive, according to Mr. Chung's analogy of American vs Japanese cars. As you can see, the structure barely bent. It was the egg that couldn't survive a two-story-high fall.

I think what we could've done to make the egg lander better was to cover all sides. Having an extra "leg" on each vertex of the tetrahedron may have helped, as it would spread out when the egg lander is dropped, and absorb some of the impact.

We should have also cut up leftover straws into short stubs and surround the egg with them. These stubs would've served as cushioning for the impact, because before the force of gravity can get to the egg, it must get through the stubs first. These stubs also wouldn't pierce the egg when it falls, because the sharp ends aren't touching the egg. 

Finally, I think all sides of the lander should be covered with some type of springy mechanism made from straws.  It will certainly absorb a lot of shock when dropped.

Hopefully we can build a better model next time. I'm still baffled by how college students can build a successful egg lander with ten straws, though.