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Tag Archives: cnc mill document

PLASMA BEAM MACHINING

A great deal of interest and development of plasma beam has occurred in recent years. Plasma is created by passing a gas through an electric arc. The gas is ionized by the arc, and an extremely high temperature results. Temperatures in plasma arcs can exceed ( ), many times hotter than any arc or flame …

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ULTRASONIC MACHINING

Ultrasonic machining is akin to abrasive processes like sand blasting. High-frequency sound (Figure M-113) is used as the motive force that propels abrasive particles against the workpiece. Advantages of this process include the ability to machine hard material with little distortion. Good surface finishes may be obtained, and part features of many different shapes can be …

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ELECTROLYTIC GRINDING

In the process of electrolytic grinding (ELG), an abrasive wheel much like a standard grinding wheel is used. The abrasive wheel bond is metal, thus making it a conducting Wheel-cathode medium. The abrasive grains in the grinding wheel are nonconducting and aid in removing oxides from the workpiece while helping maintain the gap between wheel and work. ELG,like ECM, is a deplating …

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SINGLE-POINT THREADING

One of the considerations in threading is the lead-in and ending of a thread (Figure M-69). When the threading operation begins, the spindle is rotating at the correct spindle speed, but the tool is not moving. Distance A, or at least part of it, is traveled while the feed rate is accelerating from zero to a …

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RECTANGULAR AND POLAR COORDINATES

Consider a blank sheet of paper on the desk before you and imagine that you wish to define specific locations on the paper relative to the center of the sheet. You could start by drawing a vertical and a horizontal line on the paper and identifying these by the letters X and Y (Figure …

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ADVANTAGES AND CAPABILITIES OF NUMERICAL CONTROL

Computer control of machine tools has numerous advantages and capabilities. One distinct advantage is rapid and high-precision positioning of both workpiece and cutting tools. Modern CNC machines can position cutting tools and workpieces at rapid traverse feed rates of several hundred inches per minute to an accuracy of .0001 in. Once programming is complete, and tooling is set up, the machine tool …

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ADDITIONAL CAPABILITIES OF THE TOOL AND CUTTER GRINDER

Additional capabilities of this machine include sharpening of reamers, taps, drills, and single-point cutting tools. Having a power-driven workhead permits cylindrical grinding (Figure L-179). The workpiece may be held in a threejaw chuck (Figure L-180) or on a magnetic grinder chuck (Figure L-181). The internal grinding attachment permits internal cylindrical grinding (Figure L-182). The swiveling capability of the workhead permits regrinding of lathe …

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CYLINDRICAL GRINDING A LATHE MANDREL

A lathe mandrel is a common and useful machine shop tool. Precision mandrels are finished by cylindrical grinding after they have been machined and heat-treated. Finish grinding the mandrel will provide you with basic experience in cylindrical grinding. Refer to a working sketch (Figure L-130) to determine the required dimensions. Selecting the Wheel For a hardened …

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SPECIFIC PROBLEMS AND SOLUTIONS IN SURFACE GRINDING (TABLE L-2)

Effect—Chatter or vibration marks (Figure L-107) Cause—Interrupted cutting due to wheel balance; wheel not concentric to spindle; external vibrations; or a “skipping wheel” resulting from loading or glazing Solution—Rebalance wheel; true wheel; re-dress wheel; relocate grinding machine and isolate from external vibration Effect—Irregular scratches or fishtails (Figure L-108) Cause—Swarf in the grinding fluid; swarf dripping from wheel …

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CARE OF GRINDER CHUCKS

Like much of the equipment found in the machine shop, grinder chucks are precision tools and deserve the same care and handling you would give your precision measuring instruments. With reasonable care they will maintain their accuracy over many years. Observe the following precautions when using grinder chucks. Step 1 Carefully clean the chucking surface before …

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