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    Lathe Machine

    Uploaded by

    Rahul Patil
    The document summarizes different types of lathes and their parts. It describes the history of lathes and how they evolved from potter's wheels. There are several types of lathes including engine lathes, turret lathes, CNC lathes, and others. The main parts of a lathe are the headstock, bed, carriage, tailstock, apron, and gearbox. The document explains the function of each part and operating mechanisms like feeds, speeds, and safety devices.

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    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    Lathe Machine

    Uploaded by

    Rahul Patil
    40 views35 pages
    The document summarizes different types of lathes and their parts. It describes the history of lathes and how they evolved from potter's wheels. There are several types of lathes including engine lathes, turret lathes, CNC lathes, and others. The main parts of a lathe are the headstock, bed, carriage, tailstock, apron, and gearbox. The document explains the function of each part and operating mechanisms like feeds, speeds, and safety devices.

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    lathe-machine

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    lathe-machine

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    The document summarizes different types of lathes and their parts. It describes the history of lathes and how they evolved from potter's wheels. There are several types of lathes including engine lathes, turret lathes, CNC lathes, and others. The main parts of a lathe are the headstock, bed, carriage, tailstock, apron, and gearbox. The document explains the function of each part and operating mechanisms like feeds, speeds, and safety devices.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    40 views35 pages

    Lathe Machine

    Uploaded by

    Rahul Patil
    The document summarizes different types of lathes and their parts. It describes the history of lathes and how they evolved from potter's wheels. There are several types of lathes including engine lathes, turret lathes, CNC lathes, and others. The main parts of a lathe are the headstock, bed, carriage, tailstock, apron, and gearbox. The document explains the function of each part and operating mechanisms like feeds, speeds, and safety devices.

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    © All Rights Reserved
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    You are on page 1of 35

    Machining Processes-

    Unit 2- Lathe
    Machine

    1
    History
    • Lathe forerunner of all machine tools
    • First application was potter's wheel
    • Rotated clay and enabled it to be formed into cylindrical shape
    • Very versatile
    • Used for turning, tapering, form turning, screw cutting, facing,
    drilling, boring, spinning, grinding and polishing operations

    2
    Types of Lathes
    • Engine lathe
    • Not production lathe, found in school shops, toolrooms, and
    job shops
    • Primarily for single piece or short runs
    • Manually operated

    3
    Engine Lathe

    4
    Special Types of Lathes
    Turret lathe
    • Used when many duplicate parts required
    • Equipped with multisided toolpost (turret) to which several different
    cutting tools mounted
    • Employed in given sequence

    5
    Turret Lathe

    6
    Special Types of Lathes
    • Single- and multiple-spindle automatic lathes
    • Six or eight different operations may be performed on many parts at the
    same time
    • Will produce parts for as long as required
    • Tracer lathes
    • Used where a few duplicate parts required
    • Hydraulically operated cross-slide controlled by stylus bearing against
    round or flat template

    7
    Special Types of Lathes
    • Conventional/programmable lathe
    • Operated as standard lathe or programmable lathe to automatically
    repeat machining operations
    • 2-axis (DRO) so can see exact location of cutting tool and workpiece
    in X and Z axes
    • Computerized numerically controlled lathes
    • Cutting-tool movements controlled by computer-controlled program to
    perform sequence of operations automatically

    8
    CNC Lathe

    9
    Lathe Size and Capacity
    • Designated by largest work diameter that can be swung over
    lathe ways and generally the maximum distance between
    centers
    • Manufactured in wide range of sizes
    • Most common: 9- to 30- in. swing with capacity of 16 in. to 12 feet
    between centers
    • Typical lathe: 13 in. swing, 6 ft long bed, 36 in.
    • Average metric lathe: 230-330 mm swing and bed length of 500 –
    3000 mm

    10
    Lathe Size

    11
    Lathe Size

    12
    Lathe Size

    13
    Lathe Size

    14
    Parts of the Lathe
    Headstock
    Tailstock

    Quick Bed
    Change
    Gearbox

    Carriage

    15
    Lathe Bed
    • Heavy, rugged casting
    • Made to support working parts of lathe
    • On top section are machined ways
    • Guide and align major parts of lathe

    16
    Lathe Bed

    17
    Headstock
    • Clamped on left-hand end of bed
    • Headstock spindle
    • Hollow cylindrical shaft supported by bearings
    • Provides drive through gears to work-holding devices
    • Live center, faceplate, or chuck fitted to spindle nose to hold and drive
    work
    • Driven by stepped pulley or transmission gears
    • Feed reverse lever
    • Reverses rotation of feed rod and lead screw

    18
    Headstock

    19
    Quick-Change Gearbox
    • Contains number of different-size gears
    • Provides feed rod and lead-screw with various speeds for
    turning and thread-cutting operations
    • Feed rod advances carriage when automatic feed lever engaged
    • Lead screw advances the carriage for thread-cutting operations
    when split-nut lever engaged

    20
    Quick-Change Gearbox

    Top View 21
    Carriage
    • Used to move cutting tool along lathe bed
    • Consists of three main parts
    • Saddle
    • H-shaped casting mounted on top of lathe ways, provides means of mounting
    cross-slide and apron
    • Cross-slide
    • Apron

    22
    Carriage

    23
    Carriage

    24
    Cross-slide
    • Mounted on top of saddle
    • Provides manual or automatic cross movement for cutting
    tool
    • Compound rest (fitted on top of cross-slide)
    • Used to support cutting tool
    • Swiveled to any angle for taper-turning
    • Has graduated collar that ensure accurate cutting-tool settings
    (.001 in.) (also cross-slide)

    25
    Cross-slide

    26
    Apron
    • Fastened to saddle
    • Houses gears and mechanism required to move carriage or
    cross-slide automatically
    • Locking-off lever inside apron prevents engaging split-nut
    lever and automatic feed lever at same time
    • Apron handwheel turned manually to move carriage along
    lathe bed

    27
    Apron

    28
    Automatic Feed Lever

    • Engages clutch that provides automatic feed to carriage


    • Feed-change lever can be set for longitudinal feed or for
    crossfeed
    • In neutral position, permits split-nut lever to be engaged for thread
    cutting
    • Carriage moved automatically when split-nut lever engaged

    29
    Tailstock

    • Upper and lower tailstock castings


    • Adjusted for taper or parallel turning by two screws set in base
    • Tailstock clamp locks tailstock in any position along bed of
    lathe
    • Tailstock spindle has internal taper to receive dead center
    • Provides support for right-hand end of work

    30
    Tailstock

    31
    Setting Speeds on a Lathe
    • Speeds measured in revolutions per minute
    • Changed by stepped pulleys or gear levers
    • Belt-driven lathe
    • Various speeds obtained by changing flat belt and back gear drive
    • Geared-head lathe
    • Speeds changed by moving speed levers into proper positions
    according to r/min chart fastened to headstock

    32
    Feed of an Engine Lathe
    • Distance carriage will travel in one revolution of spindle
    • Depends on speed of feed rod or lead screw
    • Controlled by change gears in quick-change gearbox
    • Obtains drive from headstock spindle through end gear train
    • Chart mounted on front of quick-change gearbox indicates various
    feeds

    33
    Shear Pins and Slip Clutches

    • Prevents damage to feed mechanism from overload or sudden


    torque
    • Shear pins
    • Made of brass
    • Found on feed rod, lead screw, and end gear train
    • Spring-loaded slip clutches
    • Found only on feed rods
    • When feed mechanism overloaded, shear pin will break or slip clutch
    will slip causing feed to stop

    34
    Shear pin in end gear
    train prevents damage
    to the gears in case
    of an overload

    Spring-ball clutch
    will slip when too
    much strain is
    applied to feed rod

    35

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