I started thinking about other ways I could use the coiling and joining technique I used for my tortoise, and it occurred to me that the tortoise shell was essentially half an irregular stellated polyhedron.
A polyhedron is a 3D shape with flat faces, eg a pyramid. In a stellated polyhedron, the faces, rather than being flat, are extended to form new polyhedra – like a pointy star.
So I thought I would try to make a dodecahedron (12 faces – each face is a regular pentagon). The individual elements making up the tortoise shell were a mixture of hexagons and pentagons, so I already knew how to do this shape.
But instead of making a stellated dodecahedron, where the faces point outwards, I thought I would try a concave or excavated dodecahdron, where the faces dip inwards.
Whether it’s stellated or excavated, the individual units are made in exactly the same way – it’s just that the inside is the “right” side for an excavated dodecahedron, while the outside is the right side for a stellated dodecahedron.
I used the same yarn and pattern as for the tortoise shell, as I had quite a lot of yarn! But I had a brief moment of panic when I discovered that the retailer who supplied the copper wire I used for the core was no longer stocking it! However, I round an online supplier, so all was well.
The first sample units I made were quite deep, with steeply sloping sides. But when I joined two together, I concluded that they were probably too deep. To create a dodecahedron, the units have to fold back against each other , and if they are too deep they may not be able to do this.
So I made the units shallower.
Then I joined five units together around a central unit.
Then I joined the sides to create half a dodecahedron.
Now I just need to make the other half and join them together!