Oval or elliptical turning - turning a piece using an accessory mounted to the headstock that changes the center of rotation of the piece in time with the rotation, so that a cutting tool held in a fixed position on the tool-rest cuts an oval rather than a round path on the workpiece
Therming - mounting a carrier between centers, and then mounting the small workpiece(s) to the carrier, so that the axis of the headstock/tail-stock does not pass through any of the workpieces, and each workpiece gets cut only on one face. As noted in Wood-turning Methods by Mike Darlow, the etymology of the term "therming" comes via a corruption of the name of the Greek god Hermes, who was often represented as a statue set atop a plinth with a construction characteristic of thermed work.
Segmented turning - a method of woodturning where the wood blank is constructed from many individual pieces of wood (segments) which are glued together before being turned. Many interesting patterns can be generated through the process of gluing and shaping on the lathe.
Green or wet turning - turning wood while its moisture content is above equilibrium. Often done when the wood is newly felled. May be turned to finished thickness, in which case the differential shrinkage of the wood will result in a finished piece that is not perfectly round. Alternatively, it may be "rough turned". Rough turning involves turning the piece only to its general shape, leaving enough thickness so that after turning it can be allowed to dry to equilibrium moisture content and distort. The advantage over first drying the wood then turning is that a rough turned piece dries faster, will probably distort instead of split as massive wood is wont to do, and that wet wood turns better, since it creates less dust. Rough turning is inexact science: turning wood too thick will lead to splits, turning wood too thin will lead to distortion that cannot be removed, because not enough thickness is left. Once dry, it is mounted on the lathe a second time and turned to its final form. Rough turning is typically used on most functional work and some artistic pieces.
Natural edge work - pieces which include the outside of the tree trunk or limb as the edge of the piece. Typically artistic turnings, usually bowls or hollow vessels, and usually green turned to final dimension. May include the bark or not, but pieces with bark should not have any bark damaged or missing.
Ornamental turning - also known as OT, a method in which the piece is mounted upon a rocking headstock, and a spinning tool is used to cut out exotic and decorative patterns. The device is called a rose engine lathe
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