I've turned quite a few of the truestones, including the arizona jade that Bill recomends turning on a metal lathe, with a plain hs steel 3/4 spindle gouge and a 1 inch rectangle skew. Everybody says "take light cuts" but some people may not know how to go about that, so here's MY method, and it works for me most of the time. YMMV of course. Regardless what tool you turn with the only critical part is the very edge, in the one spot where the blank hits the tool. Sounds obvious, but it's often overlooked. What is critical at that point is the angle that the length of the cutting edge hits the material, and the angle of the TOP bevel of the tool. The bottom angle is less critical, because for the most part, as long as it is less than 45 degrees to the centerline of the tool, it's not going to touch the material. But that top bevel is what actually pulls the chips (or ribbons) off after the edge cuts it. Taking a light cut means that that the angle between that top bevel (or surface, if you are using a gouge), and the face of the material, is as large as possible.
Now how does that translate into english, for the geometrically challenged? If you have your tool rest set 1/4 inch below the centerline of the blank, and you are turning with a gouge that is 1/4 inch thick and you put it on the toolrest with the handle straight out (parallel with the benchtop and perpendicular to the toolrest, the angle that the inside surface of the gouge meets the material is 90 degrees. That is almost guaranteed to cause a catch or chip or some sort of badness to happen. If you move the handle right or left, and change nothing else, you are cutting at a different spot on the curve of the gouge, where the angle is much larger and less likely to catch due to the shape of the gouge. If you drop the butt of the tool down and push the tool in, you are now cutting much higher up on the blank, and the angle of incidence between the material and the inside surface of the gouge is again larger and more likely to cut rather than catch. (up until the point where the bottom bevel of the gouge touches the material, at which point it will lift the cutting edge away from the work, and you stop cutting.
So, given those two concepts, and adding in that the toolrest can be adjusted up and down, as well as in and out, you can set that critical angle to almost any value you want, again until the bottom bevel of the tool lifts the cutting edge off the workpiece. The max angle you can achieve is largely dependant on how you grind your gouge, but is usually somewhere between 120 and 140 degrees.
When somebody says "take light cuts" they mean adjust your tool to get as large an angle of incidence as possible, and use light pressure to hold it against the workpiece. It is also helpful to move the tool into contact with the piece SLOWLY!!!
One easy way to do this is to intentionally set the tool down on the toolrest where the workpiece will hit the bottom bevel of the tool first (and no cutting happens) then slowly slide the tool back while raising the butt until the edge contacts the workpiece, and you start seeing find dust or whisps of material being removed. That is the lightest cut possible usually, and you want to decrease that angle slowly until you reach that magical point where you are removing material as fast as possible, but just before it catches, or chips the blank down to the tube, or otherwise ruins your day. Just where that mystical point is and how to get there? That's the part you can't learn reading a computer.
So go out there and PRACTICE!!!
