Overview




Wood lathes work with either reciprocating or continuous revolution. The reciprocating lathe is powered by a bow or a spring, rotating the wood first in one direction, and then in the other. The turner cuts on just one side of the rotation, as with the pole lathe. The reciprocating lathe may be human-powered with a bow, as well as with spring mechanisms. The reciprocating lathe, while primitive technology requiring considerable dexterity to operate, is capable of excellent results in skilled hands. For example, reciprocating bow lathes are still used to turn beads for the Arabian lattice windows called Meshrebeeyeh that so charmed Holtzapffel in the 1880s.

Continuous revolution of the workpiece can be human-powered with a treadle wheel, or achieved with water, steam, or electric power. The style of cutting does not have the pause required by the reciprocating lathe's rotation. Even with continuous revolution, however, the turner controls the contact of tool and wood entirely by hand. The cutters are not fixed, nor advanced automatically, as with the metal-working lathe.

The nature of wood defines woodturning techniques. The orientation of the wood grain, relative to the axis of the lathe, affects the tools and techniques used by the woodturner. In spindle turning, the grain runs lengthwise along the lathe bed, as if a log were mounted in the lathe. Grain is thus always perpendicular to the direction of rotation under the tool. In bowl turning, the grain runs at right angles to the axis, as if a plank were mounted across the chuck. When a bowl blank rotates, the angle that the grain makes with the cutting tool continually changes between the easy cuts to two places per rotation where the tool is cutting across the grain and even upwards across it. This varying grain angle limits some of the tools that may be used and requires additional skill from the turner.

Moisture content affects both the ease of cutting wood and the final shape of the work when it dries. Wetter wood cuts easily with a continuous ribbon of shavings that are relatively dust-free. However, the wet wood moves as it dries. shrinking less along the grain. These variable changes may add the illusion of an oval bowl, or draw attention to features of the wood. Dry wood is necessary for turnings that require precision, as in the fit of a lid to a box, or in forms where pieces are glued together.

The character of the wood creates other challenges for the woodturner. Turners of hardwoods and ivory select different tools than those used for cutting softwoods. Voids in the wood require higher lathe speeds, fillers, or extra safety precautions. Although other woodworkers value tight, straight grain, woodturners often search out the unusual wood from roots, defects, or diseased portions of trees.

The craft of woodturning is preserved and advanced by a community of practitioners. Until the 1970s, an apprentice system in the U.K., and Industrial Arts education in the U.S., preserved many of the traditional skills of the craft. Between 1975 and 1985, industrial arts teachers, hobbyists, artists, collectors, and tool suppliers developed the symposium format for exchange of information about the craft. This community was a kind of prototype for the artisan-based maker culture active in the 21st century. The community organizes regional, national, and international symposiums, publishes journals, and hosts travelling experts at club events. Most publications and DVDs are of the DIY variety, including numerous YouTube videos.

Comments

Popular posts from this blog

Tools

Techniques

History