types of lath machine

Types of Lathe Machines

Lathes perform the machining operation known as "turning." In turning, material is removed from a workpiece by rotating it against a tool. Turning is an important manufacturing operation in the production of many metal, plastic and wood parts. Lathes can be either manually operated or computer controlled (CNC). Lathes can have have many variations, special features and attachments to facilitate a wide range of jobs.

Wood Lathes

1. The simplest lathe type is the wood lathe. As the name suggests, it is designed for turning wood. Wood lathes are small machines consisting of a bed, headstock, tailstock and tool rest. There are no precision ways as are found on a metal-working machine, since the cutting tools are moved by hand and not by machine power. Great skill is needed to control the cutting tool to accurately turn smooth curves and complex contours on the work piece.
   
   The spindle is usually driven by a belt connected to a motor, and speed changes are made by manually moving the belt to one of several pulleys mounted to the back of the spindle.
   
   Lathe tools are held manually against the work, with the support of the tool rest. The tool rest is adjustable and is clamped to the bed at a position convenient for the operation at hand.

Turret Lathe

1. Turret lathes are used in production machine shops where several sequential operations are needed on single workpiece. It is costly and time consuming to remove a workpiece from one machine and hold it in another. Removing and reholding a workpiece also introduces errors in work alignment and machining accuracy.

Engine Lathes

1. Engine lathes are the classic metal turning workhorses of the production machine shop. They come in many sizes and are adaptable to working virtually any material. These machines have a longitudinal bed to which is mounted a headstock and tailstock.
   
   As in the wood lathe, the headstock contains the spindle. However, the spindle drive is more complex, including variable speed capability or selectable gearing to provide a much wider range of speeds.
   
   A carriage moves back forth on bed ways for longitudinal turning. A cross-slide and compound rest are mounted to the top of the carriage to provide cross and angular cutting capability.
   
   The lathe cutting tools are moved against the work manually using hand wheels or automatically under the power of a lead screw that is driven by gears in the headstock.

Toolroom Lathe

1. The tool room lathe is a small- to medium-sized engine lathe specially designed for high-precision work. These machines find use in tool and die shops, where custom parts and precision fixtures are produced, often in support of production machining operations.
   
   Tool room lathes are manufactured with special attention to spindle accuracy, smooth operation and precise alignment of the carriage and cross slide. A tool room lathe is capable of better accuracy and precision than a standard engine lathe.
2. The turret lathe has a rotating turret mounted to the carriage so that as soon as an operation with one tool is completed, the turret is indexed to bring another tool into working position. The part is then machined again without having to remove it from the chuck or collet. Eight (or more) different operations can be performed on a workpiece using this type of machine.

CNC Lathe

3. Computer numerically controlled lathes have largely supplanted engine lathes in production machining environments. CNC lathes offer the advantages of greater powered axis drives, feedback control to monitor and maintain tool positioning and high-speed repeatability of complex machine motions. Once a program is verified, an operation can be quickly set up again without the need for tedious manual adjustments.
   
   CNC lathes excel at cutting curved contours without the need for specially shaped tools. This is done by programmed variation of the speed of two motion axes and the spindle simultaneously---an operation that is impossible with an engine lathe.
   

parts of lath machine

The Bed

The lathe bed is a mounting and aligning surface for the other machine components. Viewed from the operating position in front of the machine, the headstock is mounted on the left end of the bed and the tailstock on the right. The bed must be bolted to a base to provide a rigid and stable platform. The bed ways are a precision surface (or surfaces) on which the carriage slides left and right during machining operations. The ways are machined straight and flat and are either bolted to the top of the bed or are an integrally machined part of the bed.

Headstock

The headstock holds the spindle and drive mechanism for turning the work piece. The spindle is a precision shaft and bearing arrangement rotated directly by a motor or through a motor-driven belt. Gears or sliding pulleys mounted at the rear of the headstock allow spindle speed adjustment.
A work piece is held in the spindle for turning or drilling by a jawed chuck or a spring collet system. Large, unusual shaped, or otherwise difficult to hold pieces, can be attached to the spindle with a face plate, drive dogs and special clamps.

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Tailstock

The tailstock supports long work that would otherwise sag or flex too much to allow for accurate machining. Without a tailstock, long pieces cannot be turned straight and will invariably have a taper. Some tailstocks can be intentionally misaligned to accurately cut a taper if needed. The tailstock has a centering device pressed into a shallow, specially drilled hole in the end of the work piece. The center can be either "live" or "dead." Live centers have a bearing, allowing the center to rotate along with the work piece. Dead centers do not rotate and must be lubricated to prevent overheating due to friction with the work piece. Instead of a center, a drill chuck can be mounted in the tailstock.

Carriage

The carriage provides mounting and motion control components for tooling. The carriage moves left and right, either through manual operation of a hand wheel, or it can be driven by a lead screw. At the base of a carriage is a saddle that mates and aligns with the bed ways. The cross-slide, compound rest and tool holder are mounted to the top of the carriage. Some carriages are equipped with a rotating turret to allow a variety of tools to be used in succession for multi-step operations.

Cross Slide

The cross-slide is mounted to the top of the carriage to provide movement perpendicular to the length of the bed for facing cuts. An additional motion assembly, the compound rest, with an adjustable angle, is often added to the top of the cross slide for angular cuts. The cutting tools that do the actual metal removal during turning are mounted in an adjustable tool holder clamped to the compound rest.

Lead Screw

The lead screw provides automatic feed and makes thread cutting possible. It is a precision-threaded shaft, driven by gears as the headstock turns. It passes through the front of the carriage apron and is supported at the tailstock end by a bearing bracket. Controls in the apron engage a lead nut to drive the carriage as the lead screw turns.

information lath machines

1. lathe , machine tool for holding and turning metal, wood, plastic, or other material against a cutting tool to form a cylindrical product or part. It also drills, bores, polishes, grinds, makes threads, and performs other operations. Its principal parts are the headstock (attached to the bed or base of the machine), which holds one end of the material in a rotating spur; the tailstock, which holds the other end, moves along the bed, and can be clamped in position at any point; the cutting tool; and the power feed, comprising the drive and its motive parts.