Center lathe by mikesanye

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									Centre lathe
• The Centre Lathe is used to manufacture cylindrical
  shapes from a range of materials including; steels and
  plastics.

• Components that assemble to make an car engine work
  have been made using lathes.

• The Lathe may be operated by people (manual lathes)
  or computer controlled lathes (CNC machines) that
  have been programmed to carry out a particular task.
     A basic manual centre lathe

• The lathe is
  controlled by a
  person turning
  handles on the
  top slide and
  cross slide in
  order to make a
  part.
                 Lathe Parts
• Lathe bed
 Made from rigid cast Iron
 Accurately machined
  slideways
 Slideways guide carriage
  & tailstock
 Headstock on upper end
  of the lathe bed
Lathe parts

      • Headstock
       Holds lathe spindle
        and gears
       Chuck is fitted to
        spindle
       Spindle is hollow for
        long bars
               Lathe parts

• Tailstock
 Can be moved along
   slideways
 Can be clamped
in any location
 Inside tapered
to hold drill chuck
Lathe parts

       • Carriage
        Moves along bed
         between tailstock and
         headstock
        Saddle – across the
         lathe
        Apron – hangs down
         in front
                 Lathe parts

• Cross Slide
 Fitted on the Saddle
 Moves cutting tool at
  right angles to lathe
  bed
Lathe parts

    • Top Slide
      (Compound slide)
     Fitted to top of Cross slide
     Carries toolpost and cutting
      tool
     Can rotate to any angle
     Is used to turn tapers
                     Lathe parts

• Feed shaft
 Used to move the
  Carriage
  automatically

• Lead screw
 Used when screw
  cutting on the lathe
Lathe Parts
      • Three Jaw Chuck
       Self centring
       Holds round and
        hexagonal work
       3 jaws are connected
       Jaws are stamped 1,2 & 3
        and fitted in order
       Chuck key used to open
             Lathe parts
• Toolpost
 Fitted on top slide and
  carries the cutting tool
  or the cutting tool
  holder
 Can adjust the height
  on some types
 Can carry 4 different
  tool holders
Lathe parts

      • Tool holders
       Used for holding
        cutting tool bits
       Available in Right
        hand, left hand and
        straight
• Cutting Tools
 Can be High Speed
  Steel held in tool
  holders
 Can be also Ceramic
  (Tungsten carbide)
  bits held directly in
  toolpost
          Cutting Tool Angle
• Clearance angle
 Ensures only the
  cutting edge of the
  tool touches the work
 Too much clearance
  causes chatter
Cutting tool angle
         • Rake Angle
          Allows the chip being cut
           to flow out
          Changing the rake
           changes the power used in
           cutting and the heat
           generated
          Large rake = soft ductile
           materials
          Small rake = hard brittle
           materials
            Cutting tool angle
• Tool bits are held in
  holders at an angle of
  about 15°
                 Cutting tools
• We can put different shapes on the High
  speed tool bits to cut different shapes on the
  workpiece
Lathe operations
        Facing off



        Parallel Turning



        Parallel Turning
                   Parallel Turning
• The tool moved parallel to
  the work and cylindrical
  shapes are
  formed




• Also known as sliding
             Parallel Turning
• The student can Parallel turn the work on the
  lathe manually or use the automatic traverse
  option
Facing off
        • The tool is moved at
          right angles to the
          work using the cross
          slide
        • Flat surfaces are
          produced
                    Knurling
• A knurling tool is used to press a pattern onto a
  round section.
• The pattern is normally used as a grip for a
  handle.
• This provide a grip for the round part
  e.g. Screwdriver
Knurling
                     Parting off
• If the student wants to cut
  off the part they have
  turned, they can use the
  hacksaw and a vice or use
  the parting off tool on the
  lathe.
Setting the tool height
               • The cutting tool on the
                 lathe must be set to the
                 exact centre of the
                 work-piece
               • We use the centre of
                 the tailstock to guide
                 us to the correct height
       Screw-cutting on the lathe
• Lathes are also used to
  cut threads in round
  bars
• These threads take up
  different profiles e.g
  iso (60°) ACME etc.
• These threads can be
  seen on bench vices,
  lathes etc.
CNC Lathes
• In Industry it is not
  efficient or profitable to
  make everyday products
  by hand.
• On a CNC machine it is
  possible to make hundreds
  of the same item in a day.
• First a design is drawn
  using design software,
  then it is processed by the
  computer and made using
  the CNC machine.
• In industry, CNC
  machines can be
  extremely large.
       LATHE OPERATIONS
    Producing a Flat Surface




             Producing a
             Cylindrical Surface

.




           Taper Turning
Radius Turning Attachment




                            Drilling on a Lathe




            Parting Off / Under Cutting

								
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