Types of Milling Machines

Milling machines are among the most versatile and useful machine tools due to their capabilities to perform a variety of operations. They can be broadly classified into the following types:

  • Column and knee type of milling machines
  • Bed type
  • Rotary table
  • Tracer controlled

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         Horizontal Milling Machine             Vertical Milling Machine

    ((Kalpakjian S., Introduction to Manufacturing Processes)

    Column & Knee type Milling Machines

    Used for general purpose milling operations, column and knee type milling machines are the most common milling machines. The spindle to which the milling cutter is may be horizontal (slab milling) or vertical (face and end milling). The basic components a re:
     

  • Work table, on which the workpiece is clamped using the T-slots. The table moves longitudinally with respect to the saddle.
  • Saddle, which supports the table and can move transversely.
  • Knee, which supports the saddle and gives the table vertical movements for adjusting the depth of cut.
  • Overarm in horizontal machines, which is adjustable to accomadate different arbor lengths.
  • Head, which contains the spindle and cutter holders. In vertical machines the head may be fixed or vertically adjustable.

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    Bed type Machines

    In bed type machines, the work table is mounted directly on the bed, which replaces the knee, and can move only longitudinally. These machines have high stiffness and are used for high production work.
     

    Planer Machines

    Planer machines are similar to bed type machines but are equipped with several cutters and heads to mill various surfaces.
     

    Rotary Table Machines

    Rotary table machines are similar to vertical milling machines and are equipped with one or more heads to do face milling operations.
     

    Tracer Controlled Machines

    Tracer controlled machines reproduce parts from a master model. They are used in the automotive and aerospace industries fro machining complex parts and dies.
     

    Computer Numerical Control(CNC) Machines

    Various milling machine components are being replaced rapidly with computer numerical control(CNC) machines. These machine tools are versatile and are capable of milling, drilling, boring and tapping with repetitive accuracy.