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Horizontal MillingMachines and
AccessoriesSession 12
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Horizontal Milling
Machines1. Manufacturing-type
Cutter height is controlled by vertical
movement of headstock2. Special-type
Designed for specific milling operations
3. Knee-and-column-type Relationship between cutter height and
work controlled by vertical movement oftable
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Manufacturing-Type
Used primarily for quantity productionof identical parts
Distinctive features
Automatic cycle of cutter and workapproach
Rapid movement during non-cutting cycle
Automatic spindle stop
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Manufacturing-Type
Two common types
Plain manufacturing type
Small plain automatic knee and columntype
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Plain Manufacturing Type
Milling Machine
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Special-Type Machines
Designed for individual milling
operations
Used for only one particular type of job Completely automatic
Employed when hundreds or
thousands of similar pieces are to bemachined
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Machining Centers
Capable of handling wide variety ofwork all in one setup
Straight and contour milling, drilling,
reaming, tapping, and boring
Capable of high production rates whilestill maintaining high degree of accuracy
Rugged construction, reliable controls
Anti-backlash ball screws
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Machining Centers
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Knee-and-Column-TypeMilling Machines Machines in this class fall into three
categories:
Plain horizontal milling machine Universal horizontal milling machines
Vertical milling machines
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Universal HorizontalMilling Machines
Difference from plain horizontalmachine is addition of table swivel
housing Located between table and saddle
Permits table to be swiveled 45 in eitherdirection in a horizontal plane
Used for milling of helical grooves intwist drills, milling cutters, and gears
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Universal HorizontalMilling Machine
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Milling Machine Parts
Base Gives support and
rigidity to machine
Acts as reservoir forcutting fluids
Column face Precision-machined
and scraped sectionused to support andguide knee whenmoved vertically
Knee Houses feed
mechanism
Attached to columnface and movedvertically
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Milling Machine Parts
Saddle
On top of knee
Moved in or out by
means of crossfeed
handwheel (manually
or automatically)
Swivel table housing
Fastened to saddle on
universal milling
machine
Enables table to be swiveled 45 either side ofcenterline
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Milling Machine Parts
Table
Rests on guidewaysin saddle and travelsleft and right
Supports vise andwork
Crossfeed handwheel
Used to move table
in and out Table handwheel
Used to move tableleft and right
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Milling Machine Parts
Feed dial
Used to regulatetable feeds
Spindle
Provides drive forattachments, arbors,cutters
Overarm
Provides for correct
alignment andsupport of arbor andvarious attachments
Can be adjusted andlocked in various
positions
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Milling Machine Parts
Arbor support
Fitted to overarm andcan be clamped
Aligns and supports
various attachments Elevating screw
Gives upward ordownward movementto knee and table
(manually orautomatically)
Spindle speed dial Set by crank used to
regulate spindle speed
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Backlash Eliminator
Eliminates backlash (play) between nut andtable lead screw Permits operation of climb (down) milling
Two independent nuts mounted on lead screw
Nuts engage common crown gear which mesheswith rack
Axial movement of rack controlled by backlasheliminator engaging knob on front of saddle
Turning knob in, nuts forced to move along leadscrew in opposite directions
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Machine BacklashEliminator
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Milling MachineAccessories
Wide variety of accessories greatlyincrease versatility and productivity
Accessories classed as fixtures orattachments
Work-holding device fastened to table
Designed to hold workpieces thatcannot be readily held in vise or whenlarge quantities are to be machined
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Milling MachineAttachments
1. Designed to hold special attachment thatincrease versatility of machine
Vertical, high-speed, universal, rackmilling, slotting
2. Designed to hold standard cutters
Arbors, collets, and adapters
3. Designed to hold workpiece Vise, rotary table, indexing (dividing)
head
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Vertical Milling Attachment
Enables plain or universal milling machine tobe used as a vertical milling machine Mounted on face of column or overarm
Angular surfaces made by swiveling head,
parallel to face of column up to 45 eitherside of vertical
Used for face milling, end milling, drilling,boring and T-slot milling
Universal milling attachment modificationallows swiveling in two planes for cuttingcompound angles
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Rack Milling Attachment
Used to mill longer gear racks (flat
gears) than could be cut with
standard horizontal milling machine
Rack indexing attachment included
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Slotting Attachment
Converts rotary motion of spindle intoreciprocating motion
Cutting keyways, splines, templates, and
irregularly shaped surfaces
Length of stroke controlled byadjustable crank
Tool slide may be swiveled to any anglein plane parallel to face of column
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Arbors
Arbors
Used for mounting milling cutter
Inserted and held in main spindle by draw
bolt
Shell-end mill arbors
Permit face milling horizontally or vertically
Fit into main spindle
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Collets and Adapters
Collet adapters
used for mounting drills or other tapered-shank tools in main spindle of machine or
vertical milling attachment
Quick-change adapter
Mounted in spindle
Permits such operations as drilling, boring,and milling without change in setup ofworkpiece
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Arbors, Collets, andAdapters
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Milling Machine Vises
Plain vise
Jaws parallel or 90 to axis of spindle
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Milling Machine Vises
Swivel base vise
Can swivel through 360 in horizontalplane
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Milling Machine Vises
Universal vise
Can swivel through 360 in horizontalplane and tilted from 0 to 90 in vertical
plane
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FixturingSystems
Easy-to-adjust Stop
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Indexing or Dividing Head
Permits cutting of bolt heads, gearteeth, ratchets
Revolve work as required to cuthelical gears and flutes in drills,reamers, and other tools
When connected to lead screw of milling
machine
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Horizontal Boring Mill
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Horizontal Boring Mill