Paper Plate Icosohedron
Step 1: Make the Template
For this project, keep an eye out for paper plates and acquire 20 of them. Make an equilateral
triangle template by folding it in half vertically and horizontally to mark the center of the plate,
and then use a protractor to measure and mark out 120, 240, and 360 degrees. Fold the edges to
the center, and you've got your template ready to go.
Step 2: Fold a Total of 20 Plates
Trace the triangle onto 19 other plates and fold them up so that they are all the same. Push down
rather strongly with your pen. This makes folding quicker and easier.
Step 3: Assembly
Staple them together and display!
Dixie Sphere
Dixie Cup Spherical Dodecahedron
All you need is a glue gun and 140 - 5 oz. Dixie Cups
These Dixie spheres exhibit icosahedral symmetry, but other kinds are possible as well.
step 1- Constructing the basic 7-cup modular unit
The Dixie sphere is composed of twenty spherical-hexagonal 7-cup modular units, which you
will construct first. Each hexagonal modular unit consists of seven cups hot-glued together such
that one central cup is surrounded tangentially by six more cups. (The spaces between cups will
look like equilateral triangles with concave edges, and the circular bases and rims of the cups
will look like hexagonal close-packing of circles, but they will possess a slight overall curvature,
as the circles define the surfaces of spheres.) It is important that the central cup contacts each of
its surrounding six cups at their bases. It's a tight fit getting six cups around a center cup. Work
quickly while the glue is hot to ensure that all upper rims and lower bases of the cups are flush,
and that there are no superfluous gaps between the bases of the cups. Make all twenty units
before assembling the Dixie sphere.
step 2 - Assmebling the modular units into a sphere
Glue two spherical hexagonal modular units together such that the gap created by the four cups
resembles a square with concave edges. Here is a picture of where two hexagonal units meet.
Two cups from one unit are glued at their bases to two cups of another unit. See the square? Glue
three more modular units to the first two to form a spherical pentagon with a hole in its center.
Repeat this process to form another spherical pentagon. Glue the two pentagons together. From
this point on, it should be obvious where to add the remaining modular units - just continue to
make more spherical pentagons and the structure will close upon itself to form a Dixie sphere.
step 3 - Some Thoughts and A Different Type of Dixiesphere
The finished spherical dodecahedron is impressively strong, but IT'S NOT A GEODESIC
SPHERE! Quite the contrary, it is comprised of a lot of minor circles on a sphere, not great
circles (aka geodesics). The cups are truncated cones (aka frustrums). I'm not really sure how to
understand the structural dynamics or statics engineering of this type of construction. If the dixie
cups were were made of thin-walled aluminum or sum shitz, and their bases were welded plates,
would the hemispheres make good strong dome structures? I'm not equipped to consider this
problem effectively. Any thoughts?
Now, here's a different variety of Dixiesphere at various stages in its construction.
Dixiesphere2
Use a 6-cup spherical triangular modular unit for Dixiesphere2.
DS2 consists of three intersecting great circles (geodesics). The openings do not occupy identical
locations on the surface of the sphere; rather, they alternate higher and lower in their placement
with respect to one another. You will discover just what I am talking about when you make DS2.
Giant Inflatable Icosahedron
Step 1: Find a lot of plastic, two rolls of duct tape, scissors, and a ruler. If possible use recycled
material.
I used 10'x25' 4mil plastic used for laying down on the floor before painting. You could use trash
bags instead, though. I thought about using Tyvec, but they claim that it is breathable, so I wasn't
sure how well it would hold air.
Step 2: Plan it out.
Lay it all out on the floor. I only laid part of it at a time, since the room I was in was too small to
be able to put it all down. Then tape it all together
Step 3: Assemble.
I taped it all together flat first with tape on both sides of the seam. This may have been overkill,
and you may be able to get away with just putting tape on one side. It was a little tricky since the
plastic didn't really want to cooperate in the small room. If I ever get ambitious and want to make
a bigger inflatable sphere, I'll need to find a big space to do it in or maybe sneak into a
community center.
At home, I filled it with a vacuum by taping the extension to the exhaust port, and at the park, I
used a little pump meant to fill up an inflatable bed.
Step 4: Play!
Giant soccer would be the ultimate picnic game. I think to preserve the ball, you'd have to say no
hands or feet!
http://blog.makezine.com/archive/2006/08/weekend_projects_picnic_g.html