My Process
I will use the piece shown above, CASCADE, to illustrate the basic technique I use in much of my work. It is both novel and pretty straightforward. Pieced or segmented work in woodturning is not new. Usually form is created by assembling rings and then stacking the rings one on top of the other to develop a particular pattern and form. I also assemble rings, but rather than stack them, I nest them in the same plane by cutting the outside and inside of adjacent diameters on a machine lathe. In the design of my pieces, each ring is of a particular height and thickness so that when I turn the form out on a wood lathe, I can create a curve, a step, an angle, or whatever I am trying to do. A few of my recent pieces (Scrambled Egg on Nest) stack rather than nest rings. Asymmetry is achieved here by making the rings taper before they are stacked. In this way I am able to create vertical forms with non-repeating designs.
In CASCADE, I begin by selecting a myrtle burl and gluing an ebony ring to the top of the bowl. I then machine the outside diameter of the first ring to the desired dimension.
The 1st holly ring is assembled and glued onto a plywood disc. Each ring in my designs has 18 segments -- for a number of practical and somewhat mystical reasons. The black stripe is pressure dyed veneer. The nylon string and maple peg clamp is the device I use the bring the segments together. I have found that if the angle cut is accurate, then minimal pressure is needed to make a good joint.
The inner diameter of the first holly ring is then turned on the machine lathe so that it fits over the 1st ebony ring. The fit needs to be very good, ideally .006, just enough for a film of glue. The outside diameter of the 1st holly ring is then turned to the desired diameter.
The 2nd ebony ring is then separately assembled and turned so that it fits over the 1st holly ring. The outside diameter of that ring is turned to the desired dimension; the 2nd holly ring, assembled and turned to the correct ID, is fit over that. The photo shows the outside diameter of the 2nd holly ring being turned. Note how the rings are offset in relation to each other. This is so the final cascade design can be shaped.
The 3rd ebony ebony ring has been assembled; its inner diameter has been turned and it has been fit over the 2nd holly ring. Here the outside diameter of that ring is being turned.
The 3rd holly ring has already been fit and the final ebony ring has been assembled and cut to the correct diameter. A thin film of glue has been applied; it is ready to be slip over the 3rd holly ring. This will complete the assembly.
CASCADE has been shaped to its final form on the wood lathe using traditional turning gouges and awaits finishing.