Universal Modeling

8/12/2019 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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Universal Modeling

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