Mike Foster
Turn a Sphere—Then Turn it into an Octahedron

I will show how to turn a sphere using the shadow method.  I will cover a bit of the basic math used mark out the blank to quickly get the wood to a shape near round, then turn the result using cup centers on the headstock and tailstock to create a sphere using the shadow method without a jig.

The resulting sphere will be marked for 8 centers that will then be used to turn the sphere between centers to create an octahedron.  During the demo I will explain how I expand on the technique to create a number of geometric forms and show some examples of the results. 


Michael Foster was born and raised in Denver, Colorado. He went to college at the University of Colorado and then obtained his DDS degree at the CU School of Dentistry.  Mike then went on to complete a 20 year career with the Public Health Service at several locations around the US.

Mike started woodworking soon after he graduated from dental school. He learned basic skills using the shop of a friend who got him interested. Mike bought his first woodworking tool, a Shopsmith, after moving to New York.   Mike started turning on the Shopsmith slowly acquiring skills by trial and error. As his turning skills increased, he outgrew the limited turning capacity of the Shopsmith and bought a Woodfast lathe in 1992 . Using his Shopsmith, his new lathe and some plans from Wood magazine, he constructed his first segmented woodturning and was hooked. Mike has designed and completed numerous segmented pieces since then. After moving to Vermont, Mike built his dream shop/studio in the first floor of his renovated barn and outfitted it with some nice tools and built their kitchen cabinets for their newly renovated house, which more than paid for the tools.   He now turns on a Robust American Beauty and loves it.

The great outdoors, the sciences, science fiction and the relationship of math and science are some of Mikes interests and provide endless sources of inspiration for his turned work.  Much of his work has roots in mathematics and exploring the intersections of math and art.  He has also been inspired by microscopic diatoms and radiolaria as well as things he finds in the great outdoors.  He has several series of math art including minimal surfaces, knots, the Fibonacci series of numbers, fractals and geometric forms.  Mike is also a serious birder and bird photographer, so a new series is developing with birds as the subject.  The series are held together by the theme, not the style.  Piercing, carving, sculpting, burning, coloring and texture are all in his arsenal and often are combined to complete a particular piece.  The idea is the starting point, from there the challenge is to design the work and puzzle out how to make it a reality using the lathe.   Each piece is different and requires innovating ways of holding the work on the lathe.  Solving these problems is what Mike finds most rewarding.