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

2 Machining Operations & Machine Tools Machine TurningMillingDrillingShaperBroacherSaw Screw Thread GearsPlanner

Milling Machine 3

Definition 4 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.

5 Milling Machine HorizontalVerticalRam

Milling Machine 6 (a) horizontal milling machine

Milling Machine 7 (b) vertical milling machine

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

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

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

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

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

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

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

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

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

Milling Operations 17 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

Milling Operations 18 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.

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

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

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

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

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

24 Milling Cutting Tools

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

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