This webpage is about making a 5v 8/15 sphere icosahedron geodesic dome model.
Icosahedron - a solid made with 20 equilateral triangles, also can be generated by placing three golden rectangles at right angles to each other and joining the corners.
This is one of the platonic solids. If each edge is divided into five parts, and the face is cut into twenty five triangles, and the resuiting points are projected onto a sphere, a 5v geodesic is formed.
This face shows the layout of struts, which are not equal in length. The chord factors are:
Each of these is multiplied by the desired radius of the dome to determine the chord length.
Here is a peel pattern for one face, with the right lengths of struts. There are twenty of these faces in a complete sphere. There are tabs around the outside for joining the faces together. The wedges between some of the triangles should be cut with a tab left on one side for closing the gap.
Notice that some of the triangles are mirrored, the cyan and magenta triangles have left handed and right handed versions.
Here are two peel patterns, which you can save to your hard drive for printing.
Print twenty of either of these and you can make a complete sphere.
To simplify things, a two face assembly peel pattern can be used.
Print ten of either of these to make a full sphere.
For a 8/15 sphere, print eight of either.
After you cut out all the pieces, the tabs can be glued with white glue which will adhere quickly if spread on in a thin coat. As you assemble the model that is not colored, you'll see that some of the tabs are not needed because they are duplicated on the adjoining edge, so they should be cut off. The colored peel pattern only has tabs where needed.
Once you have closed all the wedges your two face piece should look like this. The tabs are not shown in this picture so don't trim yours off because you don't see them here. Since we are not making a full sphere we cut the blue and green triangles off of one point. For a full sphere do not cut off the blue and green triangles, and make ten of the two face assemblies.
After you have made five of the assemblies, start joing them as shown above.
After three, add the fourth and fifth
Your assembly should look something like this, or if you are making a full sphere the extra triangles will be on the bottom. Make two of these and join them to make a full sphere.
If you are making the truncated sphere, use the remaining three two face assemblies to fill in the gaps with partial faces.