Milling Machines and Their operation

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Milling Machines & Operations:

Milling Machines & Operations 1

Submitted By : Group VI :

Submitted By : Group VI 2 Mehul Raina -133 Varun Mutreja - 134 Sahil Sehgal -135 Pranay Pandey - 136 Rohan Nayyar - 137 Anirudh R - 138

MILLING:

MILLING Milling is another basic machining process by which surface is generated progressively by the removal of chips from a work piece as it is fed against a rotating cutter. Milling operations can be classified into two broad categories 1. Peripheral Milling 2. Face Milling 3

Peripheral Milling :

Peripheral Milling 4

Peripheral Milling:

Peripheral Milling Operation performed by milling cutter to produce a machined surface parallel to axis of rotation of cutter Cutting force is not uniform throughout the length of the cut by each tooth Quality of surface generated and shape of the chip formed depends upon the rotation of cutter relative to direction of feed movement It can be either UP milling or DOWN milling 5

Up milling:

Up milling Also called conventional milling, - Wheel rotation opposite of the feed - The chip formed by each cutter tooth starts out very thin and increases its thickness - The length of the chip is relatively longer - Tool life is relatively shorter - Need more clamping force to hold the work part still. 6

Down milling: :

Down milling: Also called climb milling , - Wheel rotation is parallel to the feed - The chip formed by each cutter tooth starts out thick and leaves out thin - The length of the chip is relatively short - Tool life is relatively longer - Need less clamping force to hold the work part still. 7

Face Milling :

Face Milling 8

Face Milling:

Face Milling The generated surface is at right angles to the cutter axis It is the combined result of actions of the portions of the teeth located on both periphery and the face of the cutter Most of the cutting is done by the peripheral portions of the teeth, with the face portions provides the surface finish. 9

MILLING MACHINES:

MILLING MACHINES 10

Milling Machines:

Milling Machines The milling machine supplies an accurate rotating spindle for the cutter and a table (vise) to fix and position the work part. Types of Milling Machines are -: Column & Knee Type Fixed Bed Type Planer Type Special Type 11

Column & Knee Milling Machine:

Column & Knee Milling Machine 12 General purpose Column, spindle, cutter, table, knee, base are the common parts of the vertical and horizontal milling machines The milling machines having only the three mutually perpendicular table motions (x-y-z axes) are called plain column and knee type Vertical type is especially well suited for face and end milling operations

Horizontal Milling Machine:

Horizontal Milling Machine 13 In horizontal, arbor supports the cutter and an over arm supports arbor The vertical column houses the electrical, main drive, spindles etc mounted on a heavy base

Vertical Milling Machine:

Vertical Milling Machine 14 In vertical, milling cutters can be mounted directly in the spindle Housing (Head) can be fixed or Swiveling type Fixed Type - Head is always vertical and can be adjusted up and down Swiveling Type – Head can be swiveled to any desired angle

Slide 15:

15 Universal Milling Machine Has a table that can be rotated in a horizontal plane to any specified angle

Bed Type Milling Machine:

Bed Type Milling Machine 16

Continue...:

Continue... Bed Type Milling Machines : Designed for mass production Achieves heavier feed rates and depth of cuts, high MRR Work table is directly fixed on the bed of the machine tool The cutter mounted in a spindle head that can be adjusted vertically along the machine column Three types are available w.r.t . the count of spindles available 17

Simplex :

Simplex 18 Fixed bed replaces saddle and knee. The table has longitudinal travel only Spindle head carries spindle to which arbor is fitted to carry cutter that moves up and down along column ways

Continue...:

Continue... Duplex: Has two spindles, permitting simultaneous milling of two surfaces at a single pass Triplex: Has three spindles, permitting simultaneous milling of three surfaces at a single pass 19

Slide 20:

20 Planer type milling machines

Slide 21:

21 Consists of a fixed bed carrying a table having longitudinal movements Consists of 2 vertical columns on each side of the bed Cross rail fitter across columns can be raised or lowered Each column carries a milling head(side/horizontal) moving upwards or downwards All cutters can be operated simultaneously to machine 4 surfaces at a time

Continue...:

Continue... 22 CNC Milling Machines Cutter path controlled by numerical data Suited to profile, pocket, surface contouring.

Milling Operations :

Milling Operations 23

1. Plain Milling(Slab Milling) :

1. Plain Milling(Slab Milling) Operation of production of plane flat surface parallel to axis of rotation of plain milling cutter Cutter width extends beyond the work piece on both sides 24

2. Face Milling :

2. Face Milling The face milling cutter is rotated about an axis perpendicular to the work surface 25

Slide 26:

26 More Examples on Face Milling

3. End Milling :

3. End Milling Combination of peripheral and face milling Cutter has teeth both on end face and periphery Vertical milling machine is most suitable for end milling operation 27

4. Side Milling :

4. Side Milling Operation of production of flat vertical surface on side of work piece by using side milling cutter Depth of cut adjusted by rotating vertical feed screw of the table 28

5. Straddle Milling :

5. Straddle Milling Operation of production of flat vertical surfaces on both side of the workpiece by using two side milling cutters mounted on the same arbor 29

6. Angular Milling :

6. Angular Milling Operation of production of angular surface on a workpiece other than at right angles to the axis of milling machine spindle 30

7. Gang Milling :

7. Gang Milling Operation of milling several surfaces of the workpiece simultaneously by feeding the table against a number of cutters having same or different diameters 31

8. Form Milling :

8. Form Milling It is the operation of production of irregular contours using form cutters The contours maybe convex, concave or any other shape 32

9. Profile Milling :

9. Profile Milling It is the operation of reproduction of an outline of a template or complex shape of a master die on a workpiece 33

10.Milling Keyways, Grooves & Slots :

10.Milling Keyways, Grooves & Slots Operation of production of keys, grooves and slots of varying shapes and size by using a plane milling cutter, a metal slitting saw, an end mill or by side milling cutter 34

11. Thread Milling :

11. Thread Milling Operation of production of threads by using a single or multiple thread milling cutter. It is performed in special thread milling machine to produce accurate threads 35

Bibliography :

Bibliography 36 Reading Material Wikipedia www.howstuffworks.com www.custompart.net Workshop Tech - Hajra Choudhury Vol 2 Images/Videos Google Image Search Efunda.com Youtube.com