Cardboard Construction
St. Paul's School, Concord, NH

George Hart

Here's a large cardboard construction I made with lots of students at St. Paul's School in Concord, NH.
(There are clamps on it as the glue is still drying. Later we removed the clamps and hung it up.)

The first step was to cut out the parts using a scroll saw.  We traced the template on to 3216-inch rectangles of cardboard, then cut stacks of six sheets at a time, held together with big black binder clamps.

If you want to make your own copy of this construction, you can start with the template PDF file, which is scaled to fit in a 3216-inch rectangle.  This gives a result almost six feet in diameter, but you can scale it larger or smaller if you like. The four flaps at the ends need to be folded for gluing and the three lines in the interior are registration marks that indicate where the parts come together.

I also brought a small-scale model with me that I made from laser-cut 1/8 inch plywood. Looking at the model, you can see the single part shape appears sixty times in many different orientations.

After cutting the parts, the flaps are folded and they are assembled into groups of three, making a module you can see at left.  After the glue dried, we could take off the clamps and begin to join the modules together.

First, we fit the parts together using just clamps.  Then if everything looks right, we take the clamps off one at a time and glue the connections. The glue is brushed on to the flaps and they are re-clamped until the glue dries.

The construction gradually grew all day, starting at 8:30 until we finished at 3:30, with a few hours break for a lecture and lunch.  Different classes came and went, with over 100 students participating all together.

It is extremely rigid and we suspended it from one corner, with a three-fold axis vertical. It is something of an experiment to see how long it will last...

To better understand the process, you can watch a video of a very similar construction here.
It uses an older template which results in a triangle on the interior instead of a circle.

Thank you everyone who participated, with special thanks to Laura Hrasky, Hien Le, and Colin Callahan for arranging everything and to Jana Brown for taking these photos.