Origami dodecahedron

Origami Dodecahedron

Thanks to Max Planck for original instructions.

Take a square postit 4x4, sticky bit down and on top.
Fold the bottom half up creasing it in half forming a 2x4.
Now fold the top quarter down on the front, flip the postit over (back becomes front) and fold the top quarter down on the front (sticky bit attaches itself).
You should have a 1x4 postit, if unfolded 3x4.

                 _____________
  /\    //      |             |
 /  \  //       |             |
/    \//        |_____________|

  side              front

Fold left bottom corner to top edge and fold right top corner to bottom edge, creasing, as follows:

       _____________        ___________
      |\         \  |       \  |      |\
      | \         \ |        \ |      | \
      |__\_________\|         \|______|__\

         before                 after

Now crease a diagonal as following:

  ___________                     _        ___________
  \  |      |\                  _/|\       \  |    _/|\
   \ |      | \              _--/ | \       \ | _--  | \
    \|______|__\            /  /__|__\       \|/_____|__\
                           |  /
                           | /
                           |/

      before                crease             after

Make 30 of these (30 edges, 12 sides on a dodecahedron).

This is the FUN or tricky bit.

Play with the pieces (try this before you make the 30). First fit two together.

        __________v___
       |\       __/\  |
       |A\  __--    \B|
       |__\/_________\|
            ^
        Flaps A and B

Slot flap A on one postit into entry point v or ^ on another. Push it in until the flap goes beyond the center diagonal and the flap fold aligns (locks) with the center diagonal.

Now add a third, simultaneously slotting two postit flaps in.

Add more modules on until each flap has been slotted.

This is an example of modular origami.

There is another way to construct a regular dodecahedron. To make this, you will need...

12 sheets of A4 paper

...and that's it! Well, you've got to make it, but...

Step 1: Take your sheet of A4 and fold it in half longways. Now unfold it. Now fold it in half the other way. You have just found the centre of your piece of A4:

       1 _____________ 4
        |      :      |
        |      :      |
        |......:......|
        |      :      |
        |______:______|
       2             3

Step 2: Fold corner 1 into the middle, so that the corner just meets the middle. Do the same for the other corners, in order. You should now have a hexagon, with two short sides and two flaps (labled x and y):

           _____________
          /\     :     /\
         /  \    :    /  \
        /    \   :   /    \
       /      \  :  /  y   \
      /        \ : /        \
     /__,-¯¯-.__\:/__      __\
     \          /:\  '-__-'  /
      \   x    / : \        /
       \      /  :  \      /
        \    /   :   \    /
         \  /    :    \  /
          \/_____:_____\/

Step 3: Fold along the dotted line, and hook the two flaps together so that the whole thing stays like that. You should now have:

           ______ 1
          /      |
         /       |
       3/        |
       /         |
      /          |
     /...........|
     \           |
      \          |
       \         |
       4\        |
         \       |
          \______|
                  2

Step 4: Now you need to fold the corners 1 and 2 to touch the centre line. The fold meets the edges at points 3 and 4. To get the folds in the right place, make sure you have one straight line through 3-1-4-2. You should now be left with a pentagon:

       _
      /|¯'-,_
     / |     ¯/|
    /  | _-_ / |
   /...|/   Y..|
   \   |     \ |
    \  |      \|
     \ |    _,-'
      \|,-'¯

Step 5: Repeat steps 1-4 with your other 11 pieces of A4, to get 12 pentagons. Notice that each pentagon has one blank side, two sides with flaps on, and two sides with slits in...

Step 6: Begin slotting the pentagons together, flap into slit. Make sure that every blank edge is next to another blank edge. Get frustrated trying to put the last piece in.

And now you have a wonderful football/dodecahedron. But don't kick it!