Editing Lathe (section)

=== Components ===
[[File:Lathe.PNG|thumb|left|A metalworking lathe from 1911, showing component parts:{{ordered list|list_style_type=lower-alpha|
| bed
| carriage (with ''cross''-slide and tool post)
| headstock
| back gear (other gear train nearby drives lead screw)
| cone pulley for a [[Line shaft|belt drive]] from an external power source
| faceplate mounted on spindle
| tailstock
| leadscrew}}
]]

A lathe may or may not have legs, which sit on the floor and elevate the lathe bed to a working height. A lathe may be small and sit on a workbench or table, not requiring a stand.

Almost all lathes have a bed, which is almost always a horizontal beam, although [[CNC]] lathes commonly have an inclined or vertical beam for a bed to ensure that [[swarf]], or chips, falls free of the bed. Woodturning lathes specialized for turning large bowls often have no bed or tail stock, merely a free-standing headstock and a cantilevered tool-rest.

At one end of the bed (almost always the left, as the operator faces the lathe) is a headstock. The headstock contains high-precision spinning bearings. Rotating within the bearings is a horizontal axle, with an axis parallel to the bed, called the [[Spindle (tool)|spindle]]. Spindles are often hollow and have an interior [[Morse taper]] on the spindle nose (i.e., facing to the right / towards the bed) by which work-holding accessories may be mounted to the spindle. Spindles may also have arrangements for work-holding on the left-hand end of the spindle with other tooling arrangements for particular tasks. (i.e., facing away from the main bed) end, or may have a hand-wheel or other accessory mechanism on their outboard end. Spindles are powered and impart motion to the workpiece.

The spindle is driven either by foot power from a treadle and flywheel or by a belt or gear drive from a power source such as electric motor or overhead line shafts. In most modern lathes this power source is an integral electric motor, often either in the headstock, to the left of the headstock, or beneath the headstock, concealed in the stand.

In addition to the spindle and its bearings, the headstock often contains parts to convert the motor speed into various [[Speeds and feeds#Spindle speed|spindle speeds]]. Various types of speed-changing mechanism achieve this, from a cone pulley or step pulley, to a cone pulley with back gear (which is essentially a low range, similar in net effect to the two-speed rear of a truck), to an entire gear train similar to that of a manual-shift automotive [[Transmission (mechanics)|transmission]]. Some motors have electronic rheostat-type speed controls, which obviates cone pulleys or gears.

The counterpoint to the headstock is the [[tailstock]], sometimes referred to as the loose head, as it can be positioned at any convenient point on the bed by sliding it to the required area. The tail-stock contains a barrel, which does not rotate, but can slide in and out parallel to the axis of the bed and directly in line with the headstock spindle. The barrel is hollow and usually contains a taper to facilitate the gripping of various types of tooling. Its most common uses are to hold a hardened steel center, which is used to support long thin shafts while turning, or to hold drill bits for drilling axial holes in the work piece. Many other uses are possible.<ref>{{cite web|url=http://www.inthewoodshop.org/methods/trlathe.shtml|title=Wait a minute...|first=Howard|last=Ruttan|url-status=dead|archive-url=https://web.archive.org/web/20090108083244/http://www.inthewoodshop.org/methods/trlathe.shtml|archive-date=2009-01-08}}</ref>

Metalworking lathes have a carriage (comprising a saddle and apron) topped with a cross-slide, which is a flat piece that sits crosswise on the bed and can be cranked at right angles to the bed. Sitting atop the cross slide is usually another slide called a compound rest, which provides two additional axes of motion, rotary and linear. Atop that sits a toolpost, which holds a [[Tool bit|cutting tool]], which removes material from the workpiece. There may or may not be a [[leadscrew]], which moves the cross-slide along the bed.

Woodturning and metal spinning lathes do not have cross-slides, but rather have [[Banjo (wood lathe)|banjos]], which are flat pieces that sit crosswise on the bed. The position of a banjo can be adjusted by hand; no gearing is involved. Ascending vertically from the banjo is a tool-post, at the top of which is a horizontal tool-rest. In woodturning, hand tools are braced against the tool-rest and levered into the workpiece. In metal spinning, the further pin ascends vertically from the tool-rest and serves as a fulcrum against which tools may be levered into the workpiece.