Successfully reported this slideshow.
Your SlideShare is downloading. ×

19 ppt milling.pptx

Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Upcoming SlideShare
Milling machine(husain)
Milling machine(husain)
Loading in …3
×

Check these out next

1 of 15 Ad

More Related Content

Similar to 19 ppt milling.pptx (20)

Recently uploaded (20)

Advertisement

19 ppt milling.pptx

  1. 1. Heritage Institute of Technology Department of Mechanical Engineering Workshop/Manufacturing Practices MECH 1051 Machine Shop: Milling Machine
  2. 2. Milling Machine  A milling machine is a machine tool which is used to make surface by removing metal as the work piece is fed against rotating multipoint cutting tool.  The cutting motion is provided on the milling cutter which is a rotation.  The feed motion is provided to the job which is a linear motion.  Milling is used to make surface having good surface finish, slot, keyways and also generate gear tooth profile.  The first successful milling cutter was developed by Eli Whitney in the year 1818.
  3. 3. Machining in milling
  4. 4. Description of Milling Machine cutter
  5. 5. Basic Components of Milling Machine • Base: The base is the rigid cast iron structure attached on the shop floor which takes the entire load of the column. • Column: the column is the main supported frame mounted vertically to the base. It is box shaped and consisted with all the driving mechanisms. • Overhanging arm: It is situated at the top of the column and It extends beyond the column face provides the bearing support in one end of the arbor. • Spindle: It is located at the upper part of the column and receives power from the motor through belt pulley drive and transmit it to the arbor.
  6. 6. Continued.. • Arbor: An arbor may be considered as an extension of the machine spindle on which milling cutter is situated. The arbor may be supported at the furthest end of the overhanging arm. It is made with taper shanks for proper alignment of the machine spindle. • Knee: It is the rigid grey cast iron supporting which carries saddle and table and moves up and down along the guide ways of column. • Saddle: Saddle is placed at the top of the knee which can slides exactly at right angle to the column face. • Table: The table rests on the ways of saddle which carries the vice or holding device to hold the work piece.
  7. 7. Specification of Milling Machine  The size of the milling machine is designed by the dimensions of the working surface of the table and its maximum length of longitudinal, cross and vertical travel of the table.  In addition to that following are also required to specify- 1. number of spindle speed 2. number of automated feeds 3. spindle nose taper 4. power required floor space 5. number of axis of revolution
  8. 8. TYPES OF MILLING MACHINE The usual classification according to the general design of the milling machine. (1) Column and Knee type: (a) Hand milling machine (b) Plain milling machine (c) Universal milling machine (d) Omniversal milling machine (e) Vertical milling machine (2) Manufacturing or Fixed Bed type: (a) Simplex milling machine (b) Duplex milling machine (c) Triplex milling machine (3) Planner type: (4) Special type: (a) Rotary table milling machine (b) Drum milling machine (c) Planetary milling machine (d) Pantograph, profiling and tracer controlled milling machine
  9. 9. UP MILLING In up-milling, the feed direction of the work-piece is opposite to its rotation of cutter.  The chip thickness starts at zero and increases toward the end of the cut.  This process is called Conventional milling process.  Forces, mainly radically upward, will tend to lift the work piece from the table. The surface finish is poor in this process.  Thick chips at the exit from the cut will reduce tool life.
  10. 10. DOWN MILLING In down-milling, the feed direction of the work-piece is opposite to its rotation of cutter.  The thickness of the chip is maximum when the tooth begins its cut and reduces to minimum when the cut terminates.  The direction of the cutting force is radial downward. So the fixture design is easier  The particular milling is called climb milling.  The tool life is more and the surface finish is good.
  11. 11. VERTICAL MILLING In the vertical machine, the cutting tool and spindle move up and down A vertical milling machine's spindle axis is aligned in a vertical manner to the machine's bed. That means that the cutting tool is arranged vertically to shape the metal or other material into the desired form. The vertical mill moves while the part remains stationary. The vertical milling machine is used to produce slots, key ways etc.
  12. 12. HORIZONTAL MILLING Horizontal milling machines have a spindle or cutters mounted on a horizontal arbor above an X-Y table The cutter used here are circular type having teeth at the periphery of the cutter. The horizontal milling machine is used to mill the surface, cut the slot, chase the thread generate the gear etc. This is the most common type milling machine. The speed of the cutter is slightly more than the vertical milling machine
  13. 13. Milling operations  In milling machine following operations can be done-  Making of horizontal, vertical and angular flat surface  Making of keyways, slots, grooves etc.  Making of external and internal thread  Most importantly generation of gear tooth.
  14. 14. Milling operations To see the video click here  https://www.youtube.com/watch?v=2jc3HkrHh9s  https://www.youtube.com/watch?v=AxHexqN0Hr0
  15. 15. Thank you

×