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MILLING machines.pptx

  2. INTRODUCTION Milling is one of most important machining operations which employ a multipoint cutting tool is called milling cutter. Working Principle: In milling, the material is removed as the feed against a rotating multipoint cutter. The cutter rotates in one direction and the fixed on the table is adjusted vertically to get the required depth of cut.
  3. Types of milling Machines  Column and Knee type a) Hand milling Machine b) Plain (horizontal) Milling Machine c) Universal Milling Machine d) Omniversal Milling Machine e) Vertical Milling Machine  Fixed bed type Milling Machine  Planer type Milling Machine  Special purpose machines a) Rotary table milling machine b) Planetary milling machine c) Cam milling machine d) Profile milling machine
  4. Size of Milling Machine  The sizes of working surface of the table  The maximum length of longitudinal, cross and vertical travel of the table.  The power of driving motor  Number of feeds  Floor space required
  5. HORIZONTAL MILLING MACHINE  In milling operation the metal is removed from the work piece by rotating milling cutter  In horizontal milling machine the axis of milling cutter is parallel to the surface of work piece.  The work piece mounted on a table can be removed in three directions at right angles to each other. a) longitudinal direction to provide length of cut b) Vertical direction to provide depth of cut c) Transverse direction to provide width of cut  In normal operation the machine is operated in only one direction at a time.
  6. Construction details: The main parts of horizontal milling machine are:  Base  Column  Saddle  Knee  The work table  The over arm  Arbor support  Spindle
  7.  Base: The base is a grey cast iron which supports the column at its one end.  Column: It is a large mounted vertically on the base. On the front of the column guide ways are provided to support the knee. A dovetail slide is also provided on the top to the hold an over arm.  Saddle: The saddle is moved horizontally towards or away from the face of the column by turning the cross feed.  Worktable: The work table provides the longitudinal movement to the work by hand. The table is provided with T-slots for direct mounting of the work pieces.  Over arm: The over arm is located in the sideway at the top of the column.  Arbor support: the arbor support is positioned on the under side of the over arm. It provides support for the arbor.
  8.  Spindle: The machine spindle is located in the upper part of the column and receives power from the motor through belts, gears and clutches.  Arbor: it is fixed in the taper of the spindle nose. It locates the cutters in position, and is driven by the spindle. HAND MILLING MACHINE