First start with 270 sonobe units. This is the easy part believe me. That said, folding 270 of these things took me a long time even while I was spending long periods in hotel rooms on business with little else to do.
That done, assemble the first face. As the ball consists of hexagon faces surrounding pentagons I found it easier to start with a pentagon face made from 5 units.
Now to build up the hexagons around it. the biggest problem is these are not flat faces so lots of squinting is involved in trying to work out where each face starts.
After the pentagon face, you now need to start using 6 units per face to create the hexagons. The picture below shows what this will look like, although this is not a 'true' face as its using units from the pentagon below. Add another layer of units, until the initial pentagon is surrounded by hexagon faces.
Now the only way to describe the rest is to show the finished result.
This badly edited image shows a couple of hexagons surrounding a pentagon face. In order to get a sense of where each face goes I've used red dots to mark the centers of the faces. The important thing to remember, is from the center of one pentagon face to the center of the next pentagon face there should be two hexagon centers (indicated by red dots) in a straight line between the peaks.
The finished product should look a little like this.
Hope that helped someone. I spent a looong time trying to work that out.
