Manufacturing Processes 1 MDP 114 First Year Mechanical

Manufacturing Processes 1 (MDP 114) First Year, Mechanical Engineering Dept. , Faculty of Engineering, Fayoum University Dr. Ahmed Salah Abou Taleb 1

Machining Operations & Machine Tools Turning Planner Milling Gears Drilling Machine Screw Thread Shaper Saw Broacher 2

Milling Machine 3

Definition Machining operation in which work is fed past a rotating tool with multiple cutting edges. • Axis of tool rotation is perpendicular to feed direction. • Creates a planar surface; other geometries possible either by cutter path or shape. • Other factors and terms: • Milling is an interrupted cutting operation. • Cutting tool called a milling cutter, cutting edges called teeth. • Machine tool called a milling machine. 4

Milling Machine Horizontal Vertical Ram 5

Milling Machine (a) horizontal milling machine 6

Milling Machine (b) vertical milling machine 7

Milling Machine (b) ram type machine; ram can be adjusted in and out, and tool head can be swiveled 8

Forms of Milling Two forms of milling: (a) peripheral milling, and (b) face milling 9

Peripheral Milling vs. Face Milling Peripheral milling: ü Cutter axis is parallel to surface being machined. ü Cutting edges on outside periphery of cutter. Face milling: üCutter axis is perpendicular to surface being milled. üCutting edges on both the end and outside periphery of the cutter. 10

Milling Operations Slab Milling: The basic form of peripheral milling in which the cutter width extends beyond the workpiece on both sides 11

Milling Operations Conventional Face Milling: Cutter overhangs work on both sides 12

Milling Operations Slotting: Width of cutter is less than workpiece width, creating a slot in the work 13

Milling Operations End Milling : Cutter diameter is less than work width, so a slot is cut into part 14

Milling Operations Profile Milling : Form of end milling in which the outside periphery of a flat part is cut 15

Milling Operations Pocket Milling: Another form of end milling used to mill shallow pockets into flat parts 16

Milling Operations Surface Contouring : Ball‑nose cutter is fed back and forth across the work along a curvilinear path at close intervals to create a three dimensional surface form 17

Milling Operations Drilling: Creates a round hole in a workpart. Cutting tool is called a drill or drill bit. Customarily performed on a drill press, but can be done on a vertical mill and on a lathe. 18

Milling Operations Reaming: Used to slightly enlarge a hole, provide better tolerance on diameter, and improve surface finish. 19

Milling Operations Tapping: Used to provide internal screw threads on an existing hole. The tool is called a tap 20

Milling Operations Counterboring: Provides a stepped hole, in which a larger diameter follows a smaller diameter partially into the hole 21

Cutters for Different Types of Milling Cutters for (a) Straddle Milling, (b) form milling, (c) slotting, and (d) slitting with a milling cutter. 22

Cutters for Different Types of Milling (a) T-slot cutting with a milling cutter. (b) A shell mill. 23

Milling Cutting Tools 24

Machining Calculations • Cutting (Spindle) Speed: v = cutting speed, D = cutter diameter • Feed Rate: (mm/min) f = feed per tooth , nt = number of teeth • Material Removal Rate w = width, rpm (mm 3/min) d = depth of cut 25

Machining Calculations • Machining Time: – Slab Milling: L = length of cut, (min) d = depth of cut – Face Milling: • For single pass: • For multi-passes: w = width of cut 26