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Turning is the process used to produce cylindrical components in a lathe . It can be done manually, or using a CNC machine .
When turning, a piece of material ( wood , metal , etc.) is rotated and a cutting tool is traversed along 2 axes of motion to produce precise diameters and depths. Turning can be either on the outside of the cylinder or on the inside (also known as boring ) to produce tubular components to various geometries.
Turning can be performed manually on what are known as conventional machines with center lathes which are not computerized. In this case, they require constant supervision. Alternatively, they may be done using automatic lathes (auto lathes) operated by skilled tradesmen called machinists (or fitter and turners). Modern practice is moving towards the use of CNC controls such as a CNC turning center .
Facing is a related term. It involves moving the cutting tool across the face (or end) of the workpiece and is performed by the operation of the topslide, as distinct from the longitudinal feed ( turning ). It is commonly associated with the use of a lathe although it may be used in relation to vertical boring mills or similar operations.
The bits of waste metal from turning operations are known as turnings or swarf .
Taken from Wikipedia, the free encyclopedia
A milling machine is a machine tool used for the complex shaping of metal and other solid materials . Its basic form is that of a rotating cutter or endmill which rotates about the spindle axis (similar to a drill ), and a movable table to which the workpiece is affixed. That is to say, the cutting tool generally remains stationary (except for its rotation) while the workpiece moves to accomplish the cutting action. Milling machines may be operated manually or under computer numerical control (see CNC VTL ).
Milling machines can perform a vast number of complex operations, such as slot cutting, planing, drilling, rebating, routing, etc.
Cutting fluid is often pumped to the cutting site to cool and lubricate the cut, and to sluice away the resulting swarf .
Taken from Wikipedia, the free encyclopedia
Machining is a collection of material-working processes that involve using power-driven machine tools , such as lathes , milling machines , and drill presses , to shape metal or plastic by removing excess material. Machining is a part of the manufacture of almost all metal products. It is not uncommon for other materials to be machined. A person who specializes in machining is called a machinist . Machining is also a hobby . A room, building, or company where machining is done is called a machine shop .
Machining operations
In the strictest sense machining operations are known as chip cutting operations. That is that metal is removed, cut away, from a material in the form of small chips. These chips are analogous to the sawdust produced by operations cutting wood with a saw or drill.
Machining operations are generally classified as turning , milling , drilling , and grinding operations. There are other operations that fall into a miscellaneous category. Turning operations are operations that rotate the workpiece as the primary method of moving metal against the cutting tool. Lathes are the principal machine tool used in turning. Milling operations are operations in which the cutting tool rotates to bring cutting edges to bear against the workpiece. Milling machines are the principal machine tool used in milling. Drilling operations are operations in which holes are produced or refined by bringing a rotating cutter with cutting edges at the lower extremity into contact with the workpiece. Drilling operations are done primarily in drill presses but not uncommon on the lathes or mills. Miscellaneous operations are operations that strictly speaking may not be machining operations in that they may not be chip producing operations but these operations are performed at a typical machine tool. Burnishing is an example of a miscellaneous operation. Burnishing produces no chips but can be performed at a lathe, mill, or drill press.
An unfinished workpiece requiring machining will need to have some material cut away to create a finished product. A finished product would be a workpiece that meets the specifications set out for that workpiece by engineering drawings or blueprints . For example, a workpiece may be required to have a specific outside diameter. A lathe is a machine tool that can be used to create that diameter by rotating a metal workpiece, so that a cutting tool can cut metal away, creating a smooth, round surface matching the required diameter and surface finish. A drill can be used to remove metal in the shape of a cylindrical hole. Other tools that may be used for various types of metal removal are milling machines , saws , and grinding tools . Many of these same techniques are used in woodworking .
More recent, advanced machining techniques include electrical discharge machining (EDM), electro-chemical erosion, laser , or water jet cutting to shape metal workpieces.
As a commercial venture, machining is generally performed in a machine shop , which consists of one or more workrooms containing major machine tools. Although a machine shop can be a stand alone operation, many businesses maintain internal machine shops which support specialized needs of the business.
Machining requires attention to many details for a workpiece to meet the specifications set out in the engineering drawings or blueprints. Beside the obvious problems related to correct dimensions, there is the problem of achieving the correct finish or surface smoothness on the workpiece. The inferior finish found on the machined surface of a workpiece may be caused by incorrect clamping, dull tool, or inappropriate presentation of a tool. Frequently, this poor surface finish, known as chatter, is evident by an undulating or irregular finish, and the appearance of waves on the machined surfaces of the workpiece.
Taken from Wikipedia, the free encyclopedia
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