lathe 2

• Lathe


  Machine used to machine cylindrical shapes
• Lathe Operations


  • Turning
  • Facing
  • Boring
  • Drilling
  • Threading
  • Knurling
• Components of a lathe

  • Work piece held on a chuck which rotates in a horizontal axis
  • Used to machine cylindrical shapes
  • Provides a variety of rotating speeds and suitable manual and automatic controls for moving the cutting tool

  
• Basics of lathes


  • Work piece is held on a chuck which rotates in a horizontal axis (only in vertical lathes the chuck rotates in a vertical axis)
  • Used to machine cylindrical shapes
  • Typical lathe provides a variety of rotating speeds and suitable manual and automatic controls for moving the cutting tool

  
• Common operations possible in a lathe

  • Turning: produce straight, conical, curved, or grooved work pieces
  • Facing: to produce a flat surface at the end of the part or for making face grooves
  • Boring: to enlarge a hole or cylindrical cavity made by a previous process or to produce circular internal grooves
  • Drilling: to produce a hole by fixing a drill in the tailstock
  • Threading: to produce external or internal threads
  • Knurling: to produce a regularly shaped roughness on cylindrical surfaces
• Taper Turning Methods


  1. Use compound rest

  2. Offset the tailstock

  3. Use the taper attachment
• Compound rest


  The compound rest base is graduated in degrees and can be set at the required angle for taper turning
• Taper attachment


  The purpose is to make it possible to keep the lathe centers in line, by freeing the cross slide and then guiding it (and the tool bit) gradually away from the centerline
• Primary Machining Parameters


  • Cutting Speed (v)
  • Feed (f)
  • Depth of Cut (d)
• Cutting Speed (v)


  Primary motion, Peripheral speed (m/s or ft/min)
• Feed (f)


  Secondary motion, Turning (mm/rev or in/rev), Milling (mm/tooth or in/tooth)
• Depth of Cut (d)


  Penetration of tool below original work surface, Single parameter (mm or in)
• Material Removal Rate (MRR)


  MRR = v f d (mm3/s or in3/min)
• Types of lathes used in the industry

  • Engine Lathe
  • Bench Lathe
  • Tracer Lathe
  • Automatic Lathe
  • Turret Lathe
  • Computer Controlled Lathe
  • Vertical Lathe
• Engine Lathe


  The most common form of lathe, Motor driven, Comes in large variety of sizes and shapes
• Bench Lathe


  A bench top model, Usually of low power, Used to make precision machining works small work pieces
• Tracer Lathe


  Has the ability to follow a template to copy a shape or contour
• Automatic Lathe


  The work piece is automatically fed and removed without use of an operator, Cutting operations are automatically controlled by a sequencer of some form
• Turret Lathe


  Have multiple tools mounted on turret, Turret can be either attached to the tailstock or the cross-slide, Allows for quick changes in tooling and cutting operations
• Computer Controlled Lathe


  Highly automated lathe (cutting, loading, tool changing, and part unloading are automatic), Controlled by computer coding
• Vertical Lathe


  Chuck rotates on a vertical axis, For heavy work piece machining