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..Continued

• Recap
• Machine tool
• Lathe machine
• Basic components
• Functions

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Unit 4Machine Tools

• Machine Tools (Basic Elements, Working principle
• and Types of Operations)
  
• Lathe Machine Centre Lathe
• Drilling Machine Radial Drilling Machine
• Grinding Machine -Surface grinding, cylindrical
• 
  grinding, centerless grinding, All
• 
  operations

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Operations performed on the Centre Lathe Machine

• 1. Turning a. Straight Turning
• b. Taper Turning
• 2. Facing
• 3. Parting off
• 4. Chamfering
• 5. Knurling
• 6. Grooving
• 7. Thread Cutting
• 8. Drilling
• 9. Reaming
• 10. Boring

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Turning ..
Operations on Lathe ..

• machine length of job to reduce diameter of Job
• Cutting Tool Turning Tool
• Feed
• in direction parallel to work piece axis
• Depth of Cut
• in direction perpendicular to work- piece axis

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Turning ..
Operations on Lathe ..

• Cylindrical job

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Turning
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Turning ..
Operations on Lathe ..

• Cylindrical job

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Facing ..
Operations on Lathe ..

• machine end of job ? Flat surface
• or to Reduce Length of Job
• Cutting Tool Turning Tool
• Feed in direction perpendicular to workpiece
  axis
• Length of Tool Travel radius of workpiece
• Depth of Cut in direction parallel to workpiece
  axis

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Facing
Operations on Lathe ..

• Flat Surface/Reduce length

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Facing
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Facing
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Taper Turning
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Taper Turning
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Knurling
Operations on Lathe ..
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Knurling
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Knurling
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Grooving
Operations on Lathe ..

• Produces a Groove on workpiece
• Shape of tool ? shape of groove
• Carried out using Grooving Tool

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Grooving ..
Operations on Lathe ..
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Parting Off/cutting off ..
Operations on Lathe ..
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Operations performed on the Centre Lathe Machine

• 1.TURNING OPERATION
• 2. FACING OPERATION
• In this operation a flat surface is produced at
  the either end of the work piece. Thus by facing
  operation the length of the work piece gets
  reduced.
• The tool used for this operation is known as
  Facing Tool or regular Turning Tool, which is
  clamped in the tool post. The tool moves
  crosswise perpendicular to the centre line of the
  lathe machine with the help of Cross Slide. The
  feed rate is provided to the tool with the help
  of Carriage. During this operation the work piece
  may be rotated at higher speeds.
• 3. PARTING OFF / CUTOFFOPERATION
• In this operation, specific part of the work
  piece is removed (detached) from the total
  length of the work piece. The tool used for this
  operation is known as Parting Off Tool. The tool
  moves specific lengthwise which is parallel to
  the centre line of the lathe machine with the
  help of Carriage. The feed rate is provided with
  the help of Cross Slide. During this operation
  the work piece is rotated at lower speed.

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Operations performed on the Centre Lathe Machine

• 4. CHAMFERING OPERATION
• Basic of this operation is to remove sharp edges
  on the work piece by required angle. The tool
  used for this operation is known as Chamfering
  Tool and having the tip angle of 45o or 60o. The
  tool moves specific lengthwise which is parallel
  to the centre line of the lathe machine with the
  help of Carriage. The feed rate is provided with
  the help of Cross Slide. During this operation
  the work piece may be rotated at higher speeds.
• 5. KNURLING OPERATION
• In this operation, diamond shape pattern is
  embossed over the surface of the work piece.
  Knurling is useful to grip the work piece or the
  part of the work piece firmly. The tool used for
  this operation is known as Knurling Tool, which
  consists of set of hardened steel rollers. The
  tool moves specific lengthwise which is parallel
  to the centre line of the lathe machine with the
  help of Carriage. The feed rate is provided with
  the help of Cross Slide. During this operation
  the work piece is rotated at lower speed.

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Operations performed on the Centre Lathe Machine

• 6. GROOVING OPERATION
• In this operation, the diameter of the work piece
  is reduced over a small narrow surface for
  particular length of the work piece. The tool
  used for this operation is known as Grooving
  Tool. The tool moves specific lengthwise which is
  parallel to the centre line of the lathe machine
  with the help of Carriage. The feed rate is
  provided with the help of Cross Slide. During
  this operation the work piece is rotated at lower
  speed.

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Operations performed on the Centre Lathe Machine

• 7. THREAD CUTTING OPERATION
• In this operation, helical grooves are produced
  over the cylindrical surface of the work piece.
  For thread cutting operation definite
  relationship between the rotation of the work
  piece in the Spindle and longitudinal travel of
  the Carriage is required. This is done with the
  help of engagement of the lead screw. After
  engagement of lead screw the whole Carriage unit
  moves forwards (from tailstock towards headstock)
  and backwards (from headstock towards tailstock)
  by controlling the levers that are provided on
  the apron unit. The tool moves specific
  lengthwise which is parallel to the centre line
  of the lathe machine. The feed rate is provided
  with the help of Cross Slide. During this
  operation the work piece is rotated at very lower
  speed.

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Operations performed on the Centre Lathe Machine

• 8. DRILLING OPERATION
• In this operation, a cylindrical hole is produced
  in a work piece, by cutting edge of a cutter
  known as the drill. The drill bit is fitted into
  the barrel of the tailstock (drill is
  stationary). First the drill is bringing in
  contact to the work piece. In this position the
  tailstock is locked on to the bed with the help
  of lever provided on the tailstock, so as to
  avoid the backward movement of the tailstock. The
  feed is given to the drill with the help of hand
  wheel which is provided on the tailstock. Before
  drilling operation, centre is marked on the
  either face of the work piece with the help of
  centre drill. This is required so as to avoid the
  eccentricity or taper of the hole into the work
  piece. During the operation the drill moves in
  longitudinal direction which is parallel to the
  centre line of the lathe machine. During this
  operation the work piece is rotated at lower
  speed.

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Operations performed on the Centre Lathe Machine

• 9. BORING OPERATION
• In this operation, the hole is enlarged, which
  has been produced previously by drilling, casting
  or forging. Boring cannot originate a hole like
  drilling. Boring is used to correct error in
  concentricity and alignment in the previously
  drilled hole. The operation of boring is same as
  drilling operation.
• 10. REAMING OPERATION
• It provides sizing and finishing to the already
  drilled hole. Operation of tool and movement of
  tool is same like drilling operation. The tool
  used for reaming operation is known as reamer,
  which has multiple cutting edges. Reamer cannot
  originate a hole. It simply follows the path
  which has been previously drilled and removes a
  very small amount of material.

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Operations performed on the Centre Lathe Machine

• 11. Contour Turning
• A typical shape / curve is by using a single
  point tool.
• 12. Form Turning
• The shape of the tool is replicated on the
  workpiece.

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Lathe operations

• Turning, Facing, Parting, Thread cutting,
  Grooving, Reaming drilling, Boring, Knurling
• Milling, Grinding, Tapping, Spinning etc.

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BORING OPERATION
DRILLING OPERATION
Form Turning
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Lathe operations
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Thread Cutting Mechanism
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