To do a good spin, some basic techniques must be mastered. For a woodspin craftsman, to abandon the decoration of the details or to make the object a little more delicate, the tool must be used perpendicular to the grain of the wood in order to cut the fibers, so that the cut parts are smooth and smooth.
Turning cylindrical works of the end face is different, turning knife is easy to pick out the fiber, resulting in uneven surface.As a result, traditional shaft turning pieces have many arcs decorated with grooves, but very few cylindrical parts.
Turning tool for shaft turning
The turning tools for shaft turning include semicircle cutting tool, bevel turning tool, shallow groove semicircle knife, cutting tool and so on.The size of the tool depends on the size of the work on the one hand, on the other hand depends on personal habits of operation.
Small turning knives can only be used for small objects, while large turning knives can be used for both large and small objects (although they are not commonly used for small diameter objects or for carving small details).
Turning tools used for shaft turning (from top to bottom) : fine semicircle turning tool, bevel turning tool, spherical turning tool, cutting turning tool, shallow groove and deep groove turning tool
You usually only need a semicircle blank cutter (can be deep groove, also can be shallow groove), can be blank operation.
Bevel turning tool is the most commonly used turning tool for shaft turning.Although the bevel turning knife may give the impression that it is easy to bite, in fact, the biting problem is more serious and destructive.
In contrast, the bite problem of the bevel turning knife is acceptable and does not cause too much damage to the wood.So, you don’t have to worry too much, once you get the hang of it, you’ll be very comfortable with the bevel turning knife.
I like to use a 19 mm wide bevel turning tool for turning objects less than 75 mm in diameter.I like to use a 9 mm thick, 40 mm wide bevel turning tool for larger diameter pieces.
This knife is modified with a scraper, which is heavier, more stable and stronger than the former.In order to ensure that the bevel turning tool slides smoothly along the tool rest, it is necessary to grind the sharp corners on both sides of the turning tool into a slightly convex arc with grinding wheel or grinding rod.
Most of the details need to be handled with a fine 13 mm semicircle knife.For objects less than 30 mm in diameter, a 9 mm fine semicircle knife works better.
General methods of turning
We can spin wood to make it even and smooth without sanding it.The core of the spin is to make the rotating wood come into contact with the blade from the top down.When the blade is at a 45° Angle to the rotating wood, turning is easy and the surface is smooth.Whenever you spin, you should always keep in mind the 45° Angle.As the blade makes more and more contact with the wood, the shavings get smaller and smaller, and when the edge is upright, turning is impossible.
The smaller the Angle between the cutting edge and the wood, the larger the shavings, the higher the probability of bite.When the blade is completely level and at a 90 degree Angle to the wood, it is easy to scratch the wood, leaving an uneven surface.
The core of control rotation is to make the rotating wood contact the tool, rather than forcing the tool into the rotating wood.When the blade of the lathe knife is at the optimal Angle to the wood (about 45°), the wood touches the blade from above and the shavings are cut.
As the shavings are cut off in layers, the blade is pushed slowly towards the wood, taking care not to press the blade against the surface.
Shaft turning is the process of reducing the diameter of wood from large to small, as shown by the arrow in the figure below.
To master the necessary shaft turning techniques, you can practice with square logs with a face length of 50 ~ 65 mm and a length of 250 mm.If the wood is shorter than the tool rest, you can save a lot of time by eliminating the need to adjust the tool rest.Set up the tool rest so that you can hold the tool comfortably.
If the axis of the lathe is close to the height of your elbow, set the tool rest slightly higher than the axis.Gradually lower the height of the tool rest as the diameter of the object becomes smaller.If you are short and the lathe is tall, turn the tool rest down.If you are taller and the lathe is shorter, you should raise the tool rest.