Sonobe Modules

Project taught by Dr. Eva Szillery at the Downtown Education Collaborative in Lewiston, ME.

This module was originally designed by: Mitsonobu Sonobe

For more information about Sonobe Modules: http://www.math.lsu.edu/~verrill/origami/sonobe/index.html

The Sonobe Model shape can be used to create a cube, a stellated

octahedron, or a stellated dodecahedron. In the picture below, you can

see a finished Sonobe Model Unit (left) and a cube (right) that can be

built using six of those units.

The stellated octahedron (below) requires 12 units.

The stellated dodecahedron (below) requires 30 units.

To make the Sonobe Unit:

Step 1: Fold paper in half to form a mountain fold as shown below.

Step 2: Fold bottom edge up to the mountain fold, and top edge down

to the mountain fold. Then unfold, as shown below.

Step 3: Fold the right top corner down, and the lower left corner up

as shown below. Be sure that the triangles you create in these folds

line up with the parallel folds on the square.

Step 4: Fold the top edge down to the center crease, and the bottom

edge up to the center crease, leaving the corners tucked under as

shown below.

Step 5: Using the hypotenuse of the small triangle as a guide, fold the

bottom right corner up. The left edge of the larger triangle formed should

be perpendicular to the bottom of the rectangular shape you started with.

See below:

Step 6: Fold the top edge down to form a parallelogram.

Step 7: Tuck the loose ends in to form an envelope. This is like the

process you can use to close the top of a cardboard box without tape!

Step 8: Turn the parallelogram over as shown below.

Step 9: Fold to create a "mountain fold" in the parallelogram in such a

way that you form two congruent triangles with the fold as shown below.

Step 10: Fold each of the two triangles so that the hypotenuse of each

is bisected, creating four congruent triangles. the center "square" should

pop out toward you, and the two side triangles should have bends inward

as shown below.

Finally, make the number of units you need for the project you wish to

build. Be sure ALL of the pieces stack neatly on top of each other.

They must be identical in order to be used for building!

See below: