Manufacturing Processes 1 (MDP 114)
Transcript of Manufacturing Processes 1 (MDP 114)
First Year,
Mechanical Engineering Dept.,
Faculty of Engineering,
Fayoum University
Dr. Ahmed Salah Abou Taleb
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Manufacturing Processes 1(MDP 114)
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Machining Operations & Machine Tools
Machine
Turning
Milling
Drilling
Shaper
BroacherSaw
Screw Thread
Gears
Planner
Milling Machine
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Definition
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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.
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Milling Machine
Milling Machine
Horizontal Vertical Ram
Milling Machine
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(a) horizontal milling machine
Milling Machine
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Milling Machine
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(b) ram type machine; ram can
be adjusted in and out, and tool head can be swiveled
Forms of Milling
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Two forms of milling:
(a) peripheral milling, and (b) face milling
Peripheral Milling vs. Face Milling
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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
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Slab Milling:
The basic form of peripheral milling in which the cutter width extends beyond the workpiece on both sides
Milling Operations
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Conventional Face Milling:
Cutter overhangs work on both sides
Milling Operations
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Slotting:
Width of cutter is less than workpiece width, creating a slot in the work
Milling Operations
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End Milling :
Cutter diameter is less than work width, so a slot is cut into part
Milling Operations
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Profile Milling :
Form of end milling in which the outside periphery of a flat part is cut
Milling Operations
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Pocket Milling:
Another form of end milling used to mill shallow pockets into flat parts
Milling Operations
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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
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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 avertical mill and on a lathe.
Milling Operations
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Reaming:
Used to slightly enlarge a hole, provide better tolerance on diameter, and improve surface finish.
Milling Operations
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Tapping:
Used to provide internal screw threads on an existing hole.
The tool is called a tap
Milling Operations
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Counterboring:
Provides a stepped hole, in which a larger diameter follows a smaller diameter partially into the hole
Cutters for Different Types of Milling
22Cutters 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.
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Milling Cutting Tools
Machining Calculations
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r
mf
DLT
• Cutting (Spindle) Speed: rpm
v = cutting speed, D = cutter diameter
• Feed Rate: (mm/min)f = feed per tooth , nt = number of teeth
• Material Removal Rate (mm3/min)w = width, d = depth of cut
D
vN
fnNf tr
rfdwMRR
Machining Calculations
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r
mf
DLT
• 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
Dπ
vN
r
mf
dDdLT
r
mf
DLT
5.0
r
mf
wDwLT