Subject :- Manufacturing Processes-1 Prepared by:- Mangukiya Ketan (130940119046) Guided By :Harshal Sir Bipin Sir

Milling Machine

Introduction Milling is the machining operation in which work is fed past a rotating tool with multiple cutting edges Axis of tool rotation is perpendicular to feed direction Usually creates a planar surface; other geometries possible either by cutter path or cutter shape Other considerations and terms: Milling is an interrupted cutting operation Cutting tool called a milling cutter, cutting edges called "teeth" Machine tool called a milling machine

Construction of milling machine The basic components of these machines are as follows: Worktable: on which the work piece is clamped using T-slots. The table moves longitudinally relative to the saddle. Saddle: supports the table and can move in the transverse direction. Knee: supports the saddle and gives the table vertical movement so that the depth of cut can be adjusted and work pieces with various heights can be accommodated.

Overerarm: used on horizontal machines; it is adjustable to accommodate different arbor lengths. Head: contains the spindle and cutter holders. In vertical machines, the head may be fixed or can be adjusted vertically, and it can be swiveled in a vertical plane on the column for cutting tapered surfaces. Typical parts and shapes that can be produced with the milling operations

Types of milling machine Column-and-Knee type milling machines --- Vertical type --- Horizontal type Bed type milling machines Five-axes profile milling machines The Horizontal Milling Machine

The Vertical Milling Machine

Bed-type Milling Machine

Five-Axis Profile Milling Machine There are three principal linear and two angular movements of machine components in these types of milling machine.

Types of milling operations Conventional Milling (Up Milling) Max chip thickness is at the end of the cut Advantage: tooth engagement is not a function of work piece surface characteristics, and contamination or scale on the surface does not affect tool life. Cutting process is smooth The work piece has a tendency to be pulled upward, necessitating proper clamping.

Climb Milling (Down Milling) Cutting starts at the surface of the work piece. Downward compression of cutting forces hold work piece in place Because of the resulting high impact forces when the teeth engage the work piece, this operation must have a rigid setup, and backlash must be eliminated in the table feed mechanism Not suitable for machining work piece having surface scale.

Types of milling cutters Side and slot milling cutters :- These arbour mounted disc type cutters have a large number of cutting teeth at equal spacing on the periphery. These types of cutters are used for the operation like Straddle milling, Form milling, Slotting, Slitting as shown in figure

T-slot cutter :- Slab or Plain milling cutters :- Plain milling cutters are hollow straight HSS cylinder of 40 to 80 mm outer diameter having 4 to 6 straight or helical equi-spaced flutes or cutting edges and are used in horizontal arbour to machine flat surface as shown in figure. T-slot cutter :- Width of cutter is less than work piece width, creating a slot in the work

Face milling cutters :- The main features of these cutters are : - Large in diameter and heavy - Used only for flat surface - Coated or uncoated carbide inserts a clamped at the outer edge of the carbon steel body - Generally used for high production machining of larger jobs.

All types of milling cutters Ball Nose End milling cutters These cutters are able to produce elaborate contours and are often used in the machining of dies and molds. All types of milling cutters

Work holdings The Dividing Head :- A dividing head with corresponding tail stock for supporting longer work pieces. Work piece held in a three jaw chuck for machining. Gear teeth are being cut individually. The dividing head allows accurate indexing for each tooth position.

Angle Plates :- Angle Plates can be used for holding work pieces during milling operations. The angle bracket may need to be trued first using a DTI.

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