Introduction: Sonobe Unit Origami

The Sonobe unit is a pretty common modular origami unit. This instructable will show you how to make the basic Sonobe unit. There are several photos of each fold, so look at the pictures. The text is just a basic overview; the information is in the pictures.

If you have questions or need extra pictures just add a comment.


There are ways to do this in fewer folds, but the extra creasing steps are helpful for beginners. 

Step 1: Crease Center and Fold Edges to Center

Most of the content of this instructable is in the photos. So, look at the photos first. Then if you need further information look at the text.

1 Fold the paper in half. Unfold the paper.

2 Fold the edges into the center-line.

Step 2: Fold in Half

Fold the short side to the other short side across the dotted line.

Step 3: Fold Diagonals on Top and Bottom

1 Fold over the diagonal on the top and then unfold. Repeat on the other diagonal on the top. The top of the paper will look a little like a folded down shirt collar.

2 Repeat step 1 on the bottom half of the paper.

Step 4: Start to Form First Interlocking Point

1 Unfold the left side.

2 Flip the corner over.

3 Fold a point on the bottom left-hand corner.

4 Fold the left side back.

Step 5: Start to Form Second Interlocking Point

This step is the same as the previous step, but we are going to rotate the paper 180 degrees so we're working on the bottom left-hand side again.

1 Unfold the left side.

2 Flip the corner over.

3 Fold a point on the bottom left-hand corner.

4 Fold the left side back.

Step 6: Finish Forming Interlocking Point

1 Fold the bottom right-hand corner under the bottom left-hand corner.

2 Rotate the paper 180 degrees and repeat step 1.

Step 7: Fold Into a "W"

1 Fold along the center line.

2 Fold the two sides down. Make sure the little pockets are on the inside of the module.

Done!

Step 8: Finished Unit

This is what the finished unit looks like.

Step 9: Assembly of Units

The Sonobe unit is very versatile. You can create nearly all polyhedra with it. A quick google search will turn up hundreds of variations.

The finished piece of modular origami below is a Stellated Octahedron made with 12 Sonobe units.

The Sonobe units are typically connected in groups of three. Basically you slide the point of one unit into the pocket of another unit. 

Take a look at the images to see how to assemble units.