Materials

Each team was only given four different types of materials. Each unit of one material had a price. The only other stipulation was we couldn't "laminate"- layer 5 or more of any material. That turned out to be a problem, but more on that later. Here they are, also found on the resource page here. Anyways, our first task when given the materials was not instantly how to put them together- it was how strong were they? We then preformed a number of strength tests on each material. This consisted of a electronic force meter (in Newtons) being applied to the material until it broke. Unfortunately, due to limitations in our hardware, these results were not the most useful, as our meter only would read up to 55 Newtons of force.

Toothpicks

Cost: $18 per toothpick

Strength: ~55N (vertical)
              ~21 N (horizontal)
Mass: ~1g

Pros: Very inexpensive, strong for the size

Cons: Very small, Points on the end make for bad joints

Skewers

Cost: $97
Mass:~14g
Strength: ~55N (vertical)
              ~21N (horizontal)
Pros: Long and Strong
Cons: The most expensive

Straws

Cost: $55
Mass: Unknown

Strength: ~16N (vertical)
              ~ 3N (horizontal)

Pros:...none

Cons: Very weak, very expensive

Glue

Cost: $0

Strength: Unknown
Mass: Unknown
Pros: Can be pored over joints, holds somewhat well, free
Cons: Messy, takes multiple hours to dry

After looking at all this data, we concluded that excluding straws would be our best bet, as they were expensive and weak.

How we determined strength 

For those curious people out there, you may be wondering how exactly we determined the vertical and horizontal strengths. One of the best ways to find these out, especially if you have lots of extra materials, is to stress test them until they break. Most places have very sophisticated equipment to do this, but being a small rural school, we lack these. So we came up with our own methods. Using digital sensors to measure the forces, we pushed on the materials until they snapped. The vertical force was pushing down on the material from the round ends, while horizontal was applying pressure to create bends in the material. However, these were not all that accurate, so we use "~" to designate this. This is mostly because of the force scale only reading up to 55N. So, it is my assumption that our skewers and toothpicks are much stronger than they are shown to be here.


In the end, we made up our designs with toothpicks and skewers in mind, simply because they would be the strongest and easiest to work with.