universal modeling
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Milling machine unlike lathes they require
more power than hand drivenlathes.
Milling is the process of machining flat , curved, or
irregular surfaces by feeding the work piece
against a rotating cutter containing a number of
cutting edges.
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1. Vertical milling machines.
2. Horizontal milling machines.
These machine also classified as:
Knee-type, Ram-type, manufacturing or bed type,
and planer-type.
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The universal milling machine:
A more complex form of the milling machine
The table of universal milling machine can beswiveled through angle (up to 45 in either
direction).
The universal milling machine can be fitted with
various attachments such as :
The indexing fixture, rotary table, slotting and rack
cutting attachments and various special fixtures.
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The universal milling machine may be vertical or
horizontal machines.
The main components of these machines:
.1Ram
.2Spindle
.3Table
.4Saddle
.5Knee
.6Column
.7screw
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FEEDINGMECHANISM
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SPECIFICATIONOFTHEMACHINE
Working surface 49 1/4 x 11 (1250 x 280mm)
Number of T slots 3 x 5/8 (3 x 16mm)
Distance between T slots 2 1/2 (63mm)
Table Swivel +/- 45
Table
TransverseAutomatic Longitudinal 33 1/2 (851mm)
Automatic Cross 12 (290mm)
Automatic Vertical 18 3/4 (475mm)
Distance From Spindle to Over arm. 5 3/4 (147mm)
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Feeds
Horizontal spindle
Number of Feeds Cont. Variable Speed
Longitudinal and Cross
Feed
0 + 51 3/16 (0 + 1300mm)
Vertical Feed 0 + 15 3/8 (0 + 390mm)
Spindle Taper #40
Main Spindle Diameter 3 1/2 (88.88mm)
Arbor Milling Diameter 1 (22mm)
Number of Speeds Variable Speed
Speed Range at 50Hz 35 - 1800 RPM
Speed Range at 60Hz 42 - 2160 (10%) RPM
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Main motor
Coolant system
weight
Main Spindle 5.5 HPWorking Feeds - Quick
Traverse
2 HP
Coolant Pump 0.12 HP
Approximate Net
Weight
1800 kg
Maximum Weight Over 300 kg
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MILLINGOPERATIONS
.1Plain millingCalled surface milling or slab milling, is milling flat surfaces with
milling cutter axis parallel to the surface being milled
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2. Angular millingAngular milling, or angle milling, is milling flat surfaces
which are neither parallel nor perpendicular to the axis ofthe milling cutter. A single angle milling cutter is used for
angular surfaces, such as chamfers, serration's, and
grooves. Milling dovetails is a typical example of angular
milling.
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3. Milling dovetailsThe usual angle of cutter is 4550, 55, or 60 based on
common dovetail designs
4. Straddle MillingWhen two or more parallel vertical surfaces are machined at a
single cut, the operation is called straddle milling. Straddlemilling is accomplished by mounting two side milling
cutters on the same arbor, set apart at an exact spacing.
Two sides of the work piece are machined simultaneously
and final width dimensions are exactly controlled. Straddle
milling has many useful applications in production
machining.
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5. Milling HexagonThe work piece is usually mounted between centers in the
indexing fixture or mounted vertically in a swivel vise. Thetwo side milling cutters are separated by spacers, washers,
and shims so that the distance between the cutting teeth of
each cutter is exactly equal to the width of the work piece
area required.
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6. Face millingFace milling is the milling of surfaces that are perpendicular
to the cutter axis. Face milling produces flat surfaces andmachines work to the required length. In face milling, the
feed can be either horizontal or vertical.
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7. Gang Millingwhich two or more milling cutters are mounted on the same
arbor and used when cutting horizontal surfaces.All cutters may perform the same type of operation or each
cutter may perform a different type of operation.
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8. Form Milling.IS the process of machining
special contours composed ofCurved and straight lines , or
Entirely of curves, at a single cut.
The more common form milling
operations involve milling
half-round recesses and beads
and quarter-round radii on
Work piece
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9. Fly cuttingFly cutting is one of the most versatile milling operations. It is
done with a single- point cuttingtool shaped like a lathe tool bit. It is held and rotated by a
fly cutter arbor . formed cutters are expensive
And usually suitable only for one particular job
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10. Gear cuttingIs enough of the broken gear to grind the cutting tool to the
proper shape. It can also be used in the cutting of splinesand standard and special forms.
11. Keyway MillingThe type of key and corresponding keyway to be used
depends upon the class of work for which it is intended.
Types of keys :.1Woodruff key
.2Square - end machine keys
.3Round - end machine keys
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.1Wood ruff keyThe Woodruff keys are semi cylindrical in shape and are
manufactured in various diameters and width
2.Square - end machine keySquare-ends machine keys are square or rectangular in
section and several times as long as they are wide. For
the purpose of interchangeability and standardization,
these keys are usually proportioned with relation to the
shaft diameter
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3.Roundend- machine keyThe round-ends machine keys are square in section with
either one or both ends rounded off. These keys are thesame as square-ends machine keys in measurements.
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MILLINGCUTTERUSEDFOR
MILLINGKEYWAYS
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12. T slot millingCutting T-slots in a work piece holding device is a typical
milling operation. The size of the T-slots depends upon the
size of the T-slot bolts which will be used. Dimensions of T-
slots and T-slot bolts are standardized for specific bolt
diameters.
Selection of milling cutter:The T-slot milling cutter is thenused to cut the head space to the
prescribed dimensions.
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13. Sawing and partingMetal slitting saw milling cutters are used to part stock on a
milling machine . The work piece is being fed against the
rotation of the cutter.
14 G i
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14. Gear cuttingGear teeth are cut on the milling machine using formed
milling cutters called involute gear cutters. These cutters
are manufactured in many pitch sizes and shapes for
different numbers of teeth.
15. DrillingThe milling machine may be used effectively for drilling,
since accurate location of the hole may be secured by
means of the feed screw graduations. Spacing holes in a
circular path, such as the holes in an index plate, may be
accomplished by indexing with the index head positionedvertically.
16 B i
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16. BoringVarious types of boring tool holders may be used for boring
on the milling machine, the boring tools being provided
with either straight shanks to be held in chucks and holders
or taper shanks to fit collets and adapters. The two
attachments most commonly used for boring are the fly
cutter arbor and the offset boring head.
The single-edge cutting tool used for boring on the millingmachine is the same as a lathe cutter bit. Cutting speeds,
feeds, and depth of cut should be the same as that
prescribed for lathe operations.
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TOOLHOLDING
Methods of cutters fixation:
Types of fixation
1. Arbors
A b li d ith f th
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Arbors are supplied with one of three
tapers to fit the milling machine
spindle:1.1. Standard milling machine arbor
The standard milling machine arbor has a tapered, cylindricalshaft with a standard milling taper on the driving end and a
threaded portion on the opposite end to receive the arbor
nut.
1 2 b
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1.2. screw arborScrew arbors are used to hold small cutters that have
threaded holes.
1.3. The slitting saw milling cutter arboris a short arbor having two flanges between which the
milling cutter is secured by tightening
a clamping nut.
1 4 th h ll d illi tti b
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1.4. the shell end milling cutting arborhas a bore in the end in which shell end milling cutters fit and
are locked in place by means of a cap screw.
1.5. the fly cutter arboris used to support a single-edge lathe, shaper,
Or planer cutter bit for boring and gear cutting operations on
the milling machine.
2 Collets
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2. ColletsCollets is a form of a sleeve bushing for reducing the size
of the hole in the milling machine spindle so that small
shank tools can be fitted into large spindle recesses.
3. Chuck adapterA chuck adapter is used to
attach chucks to milling
machines having a standard
spindle end
4 S i dl d t
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4. Spindle adapterA spindle adapter is a form of collets having a standardized
spindle end.
5 Q i k h t li
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5. Quick - change toolingThe quick-change adapter mounted on the spindle nose is
used to speed up tool changing.
Tool changing with this system allows you to set up a number
of milling operations such as drilling, end milling, and
boring without changing the Set up of the part being
machined.
METHODS OF MOUNTING WORK
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METHODSOFMOUNTINGWORK
PIECES
.1Clamping Workpieces to the Table.
.2Clamping a Workpiece to the Angle Plate.
.3Clamping Workpieces in Fixtures.
.4Holding Workpieces between Centers.
.5Holding Workpieces in a Chuck.
.6Holding Workpieces in the Vise.
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