Machines and Machining Issues
Surface Roughness
Roughness Units
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� 1 Micrometer = 1mm = 1 micron = 10-6
meters |
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� 1 Microinch = 1min= 10-6
inches |
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� 1min = 0.025 mm |
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� 1mm = 40 min |
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� Human hair ~ 40 mm |
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Scallop Height w/ Ball
Nosed End Mill
Scallop Height- Ball Nose
on an Incline
Machining DOF (Degrees of
Freedom)
Turning Operations
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Turning (Performed on lathe) |
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Part is moving and tool is stationary. |
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Used to make parts of round cross
section |
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screws, shafts, pistons.... |
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Number of various lathe operations |
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turning, facing, boring, drilling,
parting, threading |
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Cutting Speeds |
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Nominally 30 - 800 ft./min. |
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Roughing cuts |
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Depth of cut greater then .02 in |
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Feed speed of .008 - .08 in/rev. |
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Finishing Cuts |
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Lower than roughing cuts. |
Lathe Components
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Machine Component (Main items) |
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Bed:�
Supports all other machine parts |
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Carriage: Slides along the machine ways |
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Head stock: Power train of system
(spindle included) |
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Tail Stock: Fixes piece at end opposite
to the head stock |
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Swing: Maximum diameter of the
machinable piece |
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Lathe tools |
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Left handed |
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Right handed |
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Threading |
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Boring |
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Groove |
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Cut-Off (Parting) |
Lathe
Lathe Operations
Milling
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Types of Milling Machines |
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Horizontal Milling Machine |
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Vertical Milling Machine (Bed &
Knee) |
Vertical Milling Machine
Components
Vertical Milling Machine
Bed Mill
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� Similar to Dynamyte milling machines |
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� No knee - Bed does not move up and
down |
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� Vertical motion possible in head only |
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� Controllable range of motion of head
larger than in knee mill (total range of motion less) |
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� Bed mill stiffer than knee mill |
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� Less versatile than knee mill |
Horizontal Milling
Machine
Types of Milling
Operations
Grinding and Abrasive
Processes
Grinding Machines
Surface Grinders
Cylindrical Grinders
Typical Arithmetic
Average Roughness