MAHA BARATHIO ENGINEERING COLLEGE,

CHINASALEM TK.,VILLUPURAM DT.,

Pre pared by:-

l.NARAYANAN,M.E.,ASST. PROFESSOR

Dept. of mechanical Engg

unit-3Milling machines

l.NARAYANAN,M.E.,ASST. PROFESSOR

Dept. of mechanical Engg.

CONTENTS

Milling

Milling Machines

Milling Operations

Specifications of Milling Machine

Grinding

Abrasives & Bonding Materials

Grinding Machines

MILLING

Milling: is a metal cutting operation inwhich the excess material from the workpiece is removed by rotating multipointcutting tool called milling cutter.

Milling machine: is a power operatedmachine tool in which work piece mountedon a moving table is machined to variousshapes when moved under a slow revolvingserrated cutter.

CLASSIFICATION OF MILLING

MACHINES

1. Column and knee milling machines

a. Plain column & knee type milling machine

- Horizontal spindle type

- Vertical spindle type

2. Bed type milling machine

3. Planer type milling machine

4. Special purpose milling machine

a. Tracer controlled milling machine

b. Thread milling machine

c. CNC milling machine

HORIZONTAL MILLING MACHINE

FIG. HORIZONTAL MILLING MACHINE

MAJOR PARTS :

1.BASE

2.COLUMN

3.SPINDLE

4.OVERARM

5.KNEE

6.SADDLE

7.WORKTABLE

Collar

VERTICAL MILLING

MACHINE

MAJOR PARTS :

1.BASE

2.COLUMN

3.SPINDLE

4.SPINDLE

HEAD

5.KNEE

6.SADDLE

7.WORKTABLE

DIFFERENCES BETWEEN HORIZONTAL &

VERTICAL MILLING MACHINES

SL. NO. HORIZONTAL MILLING MACHINE VERTICAL MILLING MACHINE

01Spindle is horizontal &

parallel to the worktable.

Spindle is vertical &

perpendicular to the worktable.

02Cutter cannot be moved up

& down.

Cutter can be moved up &

down.

03Cutter is mounted on the

arbor.

Cutter is directly mounted on

the spindle.

04 Spindle cannot be tilted.Spindle can be tilted for

angular cutting.

05

Operations such as plain

milling, gear cutting, form

milling, straddle milling,

gang milling etc., can be

performed.

Operations such as slot

milling, T-slot milling, angular

milling, flat milling etc., can be

performed and also drilling,

boring and reaming can be

carried out.

PRINCIPLE OF MILLING

COMPARISON BETWEEN UP MILLING & DOWN MILLING

SL.

NO.

UP MILLING

(CONVENTIONAL MILLING)

DOWN MILLING

(CLIMB MILLING)

01 Work piece fed in the

opposite direction that of the

cutter.

Work piece fed in the same

direction that of the cutter.

02 Chips are progressively

thicker.

Chips are progressively thinner.

03 Strong clamping is required

since the cutting force is

directed upwards & tends to

lift the work piece.

Strong clamping is not required

since the cutting force is directed

downwards & keep the work piece

pressed to the table.

04 Gives poor surface finish,

since chips gets accumulated

at the cutting zone.

Gives good surface finish, since

the chips are thrown away during

cutting.

05 Used for hard materials. Used for soft materials and

finishing operations.

MILLING OPERATIONS

Plain or slab milling

Face milling

End milling

Side milling

Slot milling

Angular milling

Form milling

Straddle milling

Gang milling

Slitting or saw milling

Gear cutting

PLAIN/SURFACE/ SLAB MILLING

FIG. PLAIN MILLING

Plain Milling:

Process to get the flat

surface on the work

piece in which the

cutter axis and work

piece axis are parallel.

Cutter: Plain/ Slab

milling cutter.

Machine: Horizontal

Milling m/c.

PLAIN/SURFACE/ SLAB MILLING

FIG. PLAIN MILLING

Work piece

Plain mill cutter

FACE MILLING

FIG. FACE MILLING

Face Milling:

Operation carried out

for producing a flat

surface, which is

perpendicular to the

axis of rotating

cutter.

Cutter: Face milling cutter.

Machine: Vertical Milling

Machine

END MILLING

FIG. END MILLING

End Milling:

Operation performed

for producing flat

surfaces, slots,

grooves or finishing

the edges of the work

piece.

Cutter: End milling

cutter.

Machine: Vertical

Milling Machine

SIDE MILLING

FIG. END MILLING

SIDE MILLING : Operation

performed for

producing flat

surfaces, slots,

grooves or finishing

the edges of the work

piece.

Cutter: End milling

cutter.

Machine: Horizontal

Milling Machine

SLOT MILLING

FIG. T-SLOT MILLING

SLOT Milling:

Operation of

producing slots like T-

slots, plain slots,

dovetail slots etc.,

Cutter: End milling

cutter, T-slot cutter,

dovetail cutter or side

milling cutter

Machine: Vertical

Milling Machine

ANGULAR MILLING

FIG. ANGULAR MILLING

Angular Milling:

Operation of

producing all types of

angular cuts like V-

notches and grooves,

serrations and angular

surfaces.

Cutter: Double angle

cutter.

Machine: Horizontal

Milling Machine

FORM MILLINGEnd Milling:

Operation of producing

all types of angular cuts

like V-notches and

grooves, serrations and

angular surfaces.

Cutter: Double angle

cutter.

Machine: Horizontal

Milling Machine

FIG. FORM MILLING

STRADDLE MILLING

FIG. STRADDLE MILLING

Straddle Milling:

Operation of machining

two parallel surfaces

simultaneously on a work

piece.

Cutter: 2 or more side &

face milling cutters

Machine: Horizontal

Milling Machine

STRADDLE MILLING

GANG MILLING

FIG. GANG MILLING

Gang Milling:

Process to get

different profiles on

the work piece

simultaneously with

two or more cutters

at one stretch.

Cutter: Different

cutters as required.

Machine: Horizontal

Milling Machine

GANG MILLING

CLASSIFICATION OF MILLING CUTTERS1.Plain milling cutter2.Face milling cutter3. End milling cutter4.Angle milling cutter5.T-slot milling cutter6.Slitting milling cutter7.Form milling cutter8.Fly cutter9.Woodruff key slot milling cutter

1.Plain milling cutter

The most commonmilling cutter is knownas a plain millingcutter. It is merely ametal cylinder havingteeth cut on itsperiphery forproducing a flathorizontal surface

1(a).SLAB MILLING CUTTER• Cutter width extends beyond the work piece

on both sides

• Process where axis of cutting tool is

parallel to the work piece surface to be

machined

• Used to create flat surfaces or slots

• Cutter may have either straight or helical teeth

1(a).SLAB MILLING CUTTER

1.Plain milling cutter

2.SIDE MILLING CUTTER

Side milling cutters have teeth on its

periphery and also on one or both of

its sides. They are intended for

removing metal from the sides of the

work piece. There are different types

of side milling cutters namely face

and side milling cutter, half side

milling cutter.

2.SIDE MILLING CUTTER

3.END MILLING CUTTERS

These cutters have cutting

teeth on the end as well as on

the periphery of the cutter. It

is made of two parts – body

and shank. The shanks of the

cutter may be straight or

taper.

3.END MILLING CUTTERS

4.Metal slitting saw• It is intended for cutting narrow,

deep slots and for parting off

operation. The teeth are cut on the

circumference of the cutter. The

width of the cutter is limited. The

outside diameter of the cutter will

be up to 200mm and width of the

cutter ranges from 0.75mm to

7mm.

4.Metal slitting saw

5.Angle milling cutterThe teeth of the angle milling

cutter are not parallel to the axis but

are at an angle to it. By using angle

milling cutter, inclined surfaces,

bevels and helical grooves are

machined. There are two types of

angle milling cutter

1. Single angle milling cutter and

2.double angle milling cutter.

5.Angle milling cutter

6. ‘T’ – Slot milling cutter.It is a special form of end

mills intended for machining‘T’- slots. It looks like a sidemilling cutter with a shank. Thecutters have cutting teeth onthe periphery as well as onboth sides of the cutter.

6. ‘T’ – Slot milling cutter.

7. Fly cutterFly cutter is the simplest form of cutter. Itconsists of a single point cutting toolattached to the end of the arbor. Thecutting edge may be formed to reproducea contoured surface. They are used whenstandard cutters are not available. Thework is done very slowly because of asingle cutting edge.

Fly cutter

8.Formed cutter

Formed cutters have irregularprofiles on their cutting edges toproduce required outlines on thework. Concave and convex millingcutters are used to produceconvex and concave surfacesrespectively.

SPECIFICATIONS OF MILLING MACHINE

1. Size of the work table: expressed in length x width Eg: 1500 x 30mm.

2. Longitudinal movement: Total movement of table in mm(X-direction). Eg:800mm

3. Transverse movement: Total movement of saddle along with table in mm(Y-direction). Eg:200mm

4. Vertical movement: Total movement of table, saddle & knee in mm mm(Z-direction). Eg:380mm

5. Range of the speed: Speed variation in the gear box in RPM. Eg: 45 to 200 rpm.

6. Power capacity of the motor in HP. Eg: 2 HP

Thank You….!!!!!!!!!!!