Forging D20 icosahedron

The idea is to be able to generate all of the points on a sphere as a forging guide for a D20 (regular icosahedron)

1)once the sphere has been forged take the measurement of the diameter.
2) Divide the diameter by 2 to get the Circumradius of the icosahedron.(circumradius is the distance from the the center to one of the points(vertexes))
3)The distance between any to points on a regular icosahedron is the edge length.
4)Use the site and enter 1/2 the diameter as the circumradius and take the edge length. (a radius of 1 gives an edge length of 1.05146)
5)Center punch a single point on the sphere and scribe a circle on the sphere the edge length away.
6)center punch a point anywhere on this circle.
7) use this second point to scribe another circle which will generate the next 2 intersections.
8)keep scribing and punching intersecting circles until all of the vertexes have ben defined and center punched.