1. First let’s learn some basic twist nomenclature. There are two common styles of twists that have been used for fancy furniture construction, architectural columns, and, not infrequently, candlesticks, for centuries: the rope and barley twists. Rope twists were named for their resemblance to a braided rope, and the barley twist for the barley sugar candies that were traditionally made into twisted shape.
In general, barley twists are cut deeper than rope twists. This photo shows a single barley twist that is said to have one start. A double twist has two starts, and so forth. The humped-up part of the twist is called the bine. The pitch is the length required for a start to make one full rotation.
2. This is a double barley, a very common twist used for hundreds of years. Traditionally the pitch has been twice the diameter of the workpiece, as it is here.
3. This is a four-start barley twist with a pitch that is four times the diameter of the turning square.
4. This is an example of a rarely used six-start barley. The router bit used to create this twist on the Legacy Mill is quite small.
5. This is a variation on the barley twist in which the bines have been opened to form an open twist. In this case the basic twist was a double barley, but three or four starts can be used as well.
6. This is a classic triple rope. Note that the cuts made by the router bit are shallower than that of the barley bit. The pitch is traditionally the diameter of the wood multiplied by the number of starts, as in this case.
7. Over the past year, I have experimented with extending the pitch of my rope twists, especially with highly figured woods. I feel that this shows off the figure and texture of the wood better than the tighter spiral. This is a double rope with a very long pitch.
8. This is a three-start rope twist with a long pitch. Compare this to the more traditional rope in Figure 6. And, by the way, you can see that twists can have left and right hand spirals.
9. One is not limited, of course, to the traditional rope and barley twists. Anything you can attach to the router can be made to spiral around a turning square. In this case, I used a bit with a V-shaped point at the tip to make this eight-start twist. The tricky part here was picking the number of starts and the depth of the cut so that it produced these sharp-edged ridges. Only a rosewood (camatillo in this case) would allow this kind of precise turning and maintain the knife-like edge.
10. This is a single start corkscrew twist that I have used only once (on Nadezhda).
11. This was a very tricky twist that required a variation in the starting points of this eight-start barley in a staggered manner around the indexing plate of the Legacy Mill. This only appears in Susan.
12. Since it is possible to make both right and left handed twists, one can produce this sort of thing. The trick here is to not lose the precise registration of the router bit when changing out the gears of the Legacy Mill to switch the direction of rotation.
13. Sometimes it is possible to put a twist on the crown. This is tough on the poor mill, since I have to tilt the rails as much as I possibly can, which throws the driving gears out of parallel and the whole thing makes very unhappy noises as the twist is made. This is a six-start barley.
14. This twist on Jocelyn represents an impossibility on my mill. It cannot produce a twist that has a variable pitch and a changing diameter. I have been told by Legacy Mills that a new six-axis CNC (computer-controlled) rig from them would probably be able to do this for some where north of $20,000. This four-inch section was done entirely by hand over the course of about 12 hours.
15. Finally, of course, not all of my twists are twists. This is free-form turning done on the lathe to whatever dimensions I think best. And, of course, it would be of African blackwood, which is the “king of all turning woods”, able to reproduce the finest detail.
Let me know if you have any questions or observations, and thanks for your attention!