A Simple Solution (15.3.12)

Where I last left off, I had a completed pyramid of four green acrylic triangles attached on the outside by contact paper.  One glaring problem is that the sides are not secure, and the edges can shift around a little and wobble.  Some solutions involved notches to add a rubber band or wire or use hot glue to fill the gap between the contact paper and the triangles.

While considering options to add stability, I decided to try an alternate strategy with the contact paper.  What if instead of lining the outside of the pyramid, line the inside?

I followed the same cutting procedure as before, except this time arranged the triangles flush against one another.  The following picture is my first attempt at this.  However, when I attached the fourth triangle with the two paper "wings," I made a slight error:

As you probably noticed, my extra wing is attached to the wrong side of the triangle.  Here's my sad attempt at forming the pyramid:

But on the second try, I got it right... 

and repeated this process with the acrylic to make two new pyramids.

An interesting property of the contact-paper-lined triangles is that they can collapse to fold in half.  One drawback to using wood is that not only does the contact paper stick less firmly as it does to acrylic, but the wood begins to splinter.  On one side, I tried hot gluing the paper to the wooden triangle for extra adhesion, which worked well but the glue left bumps under the contact paper.  Since the paper sticks much better to the acrylic I will most likely end up choosing this as my final material, although the wood is certainly pretty.

Next, I decided to experiment with the hot glue gun by filling the tip of each pyramid with hot glue to hold the sides stable.  I cut a small square of acrylic to cover the hot glue, but as you can see, I greatly overestimated the amount of hot glue necessary:

My second attempt was a little cleaner.  This acrylic pyramid is by far the sturdiest.  My next experiment will be to determine the least amount of hot glue necessary to hold the sides steady.

Although the actual engineering needed to create this pyramid is painfully simple, it achieves our objectives of creating a product with a simple design, small number of materials, and easy manufacturing process.  Initially I was worried I was taking the "easy way out" because my product does not require particularly intricate design or cut with the laser cutter and is almost painfully simple.