Origami Octahedron: The intersection of three orthogonal planes

Submitted by admin on Wed, 18/02/2009 - 11:59am

Below are the instructions to make your own modular origami octahedron. In my opinion the simplest modular origami polyhedron.

origami octahedron.

These modules require very little folding. Unlike, say, the Sonobe Unit.

Requirements

6 squares of paper, equal size. I used 9 x 9 cm square memo notes block paper in this demonstration. I wouldnt't go too big because the model won't be rigid. To small and it gets hard to handle.

6 squares of paper; 2 yellow, 2 blue and 2 red.

For the 1st time it helps to use 2 sheets of 3 different colours.

Instructions

Step 1: Creating the modules.

  1. Fold diagonally point to point.

    Fold diagonally.

  2. Unfold and fold diagonally the other points together.

    Fold diagonally the other way.

  3. Fold the top point to one of the side points.

    Fold top point to one side.

  4. Turn over and do the same on the opposite side.

    Fold the other point to the other side.

  5. Fold over one of the upper points.

    Fold over one of the upper points.

  6. Turn over and fold the final point over.

You now should have a 4 pointed star shape.

waterbomb base.

In origami this is called the balloon base or waterbomb base and can be used to make a cube (link to future instructions).

This is what it looks like unfolded.

Unfolded module

Repeat the steps above.

3 modules.

Until you have 6 identical pieces.

6 modules.

Step 2: Assembling The Modules.

First I'm going to name the points of the shapes 'arms' from now on.

Now, the assembling process. It can be a little fiddly if your squares were particularly small. 3cm (1 inch) or less. It helps to have small fingers for the smaller models!

  1. Put one arm of one colour (say red) inside that of another colour (blue).

    Put the arm of one module into that of another.

  2. Then take a piece of the 3rd colour (yellow) and put 1 of the arms inside the 'red' arm next to the one that is in the 'blue'.
  3. And then blue arm inside of the 'yellow'. This should make a triangular pyramid shape.

    Add the third piece, so that they all overlap each other.

  4. Add another 'red' piece. So that it is symmetrical to the 1st 'red' piece.

    Add 4th piece, symmetrically.

  5. Turning it over, it should look like this.

    Turned over.

  6. Add another 'blue' piece. So that it is symmetrical to the first 'blue' piece.

    Add the 5th piece.

  7. Slide the final, 'yellow', piece over the arms of the 'blue' shapes.

    Starting to add the final piece.

  8. Feed in the loose 'yellow' arms into the 'red' arms insides.

Then your octahedron should be complete.

Final Model - Octahedron.

To increase tightness and rigidity push together pairs of opposite points, working round the shape.

Finally

Here are a couple of octahedra I constructed from sweet wrappers, which I made square before proceeding.

Origami Octahedra, made from Refreshers and Fruitella wrappers.

Let me know how you get on.