About Segmented Turning

So what is segmented turning? According to wikipedia:

Segmented turning is turning on a lathe where the initial workpiece is composed of multiple glued-together parts. The process involves gluing up several pieces of wood to create patterns and visual effects in turned projects.

Segmented turning is also known as polychromatic turning.

In traditional wood turning, the template is a single piece of wood. The size, grain orientation and colors of the wood, will frame how it can be turned into an object like a bowl, platter, or vase. With segmented turning, the size and patterns are limited only by imagination, skill and patience.

While the vast majority of segmented turnings are vessels of one sort or another, strictly speaking, any turned object comprising multiple pieces of glued wood could be classified as a segmented turning. Examples include pens, salt and pepper mills, and rolling pins. By cutting and re-assembling pieces after they are turned, unique forms can be created, crossing over to pure art. See for example the work of Malcolm Tibbetts.

In addition to design skills, segmented turning demands precision woodworking skills as well as turning skills. Design and construction of a bowl blank–the wood piece mounted on the lathe for turning a vessel–requires angled miter joints cut to tolerances of as little as a tenth of one degree or better.

There are essentially two different techniques for constructing a bowl blank, ring construction and stave construction.

Ring construction is the most common. A ring-constructed blank comprises rings glued in a cylindrical stack. Though a platter or shallow bowl could be made from a single ring, stacking many rings is more typical. Apart from a lid or a base made and added after the fact, the height of the finished piece is a function of number of rings, and the height of each ring, which of course can vary for affect. Each ring comprises three or more pieces cut and glued to form a triangle, square, pentagon, hexagon, etc. The more pieces in a ring, the more challenging for the turner, because there are more opportunities for precision errors–gaps and misalignments in the joints between pieces. The individual pieces making up a ring themselves are often assembled from smaller pieces of contrasting or complementary colors to achieve striking patterns in the finished piece. This too adds to the complexity and challenge for the turner.

We will delve into all these particular segmented turning techniques and many more!