milling machine lecture
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MILLING
IE 262 Class Notes by Figen Eren 1
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IE 262 Class Notes by Figen Eren 2
MILLING
Milling is another basic machining process bywhich surface is generated progressively by
the removal of chips from a wor piece as it is
fed a rotating cutter!
Milling operations can be classified into two
broad categories
1. Peripheral Milling
2. Face Milling
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"
#wo forms of milling$ %a& peripheral milling' and %b& face
milling
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IE 262 Class Notes by Figen Eren (
Peripheral Milling
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Peripheral Milling
IE 262 Class Notes by Figen Eren )
#he a*is of the cutter rotation is parallel to the wor piece
surface to be machined in peripheral milling!
i!+p Milling
ii!,own milling
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IE 262 Class Notes by Figen Eren 6
Up milling
-lso called conventional milling,
- .heel rotation opposite of the feed
- #he chip formed by each cutter tooth starts out very thin and increases its
thicness
- #he length of the chip is relatively longer
- #ool life is relatively shorter
- Need more clamping force to hold the wor part still!
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IE 262 Class Notes by Figen Eren /
Down milling:
-lso called climb milling '
- .heel rotation is parallel to the feed
- #he chip formed by each cutter tooth starts out thic and leaves out thin
- #he length of the chip is relatively short
- #ool life is relatively longer
- Need less clamping force to hold the wor part still!
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0- MIIN3 45E-#I4N
IE 262 Class Notes by Figen Eren 7
#he basic form of peripheral
milling in which the cutter width
e*tends beyond the worpiece on
both sides
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Slotting (Slot milling):
8 Cutter width is less than the wor piece
width' creating a slot! If the cutter is very
thin' it can be used to cut a wor part intotwo' called saw milling.
IE 262 Class Notes by Figen Eren 9
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0aw milling
IE 262 Class Notes by Figen Eren 1:
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IE 262 Class Notes by Figen Eren 11
Sie milling:
Cutter' machines the side of the wor piece!
!
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Strale milling:
0imilar to side milling' but cutting taes on both sides
of the wor part simultaneously
IE 262 Class Notes by Figen Eren 12
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Form milling
8 In which milling teeth have a special profile that determines the shape of the slot that is cut in the wor
1"
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I E 2 6 2
C l a
s s
N o t
e s
b y
F i g
e n
E r e
n
1(
Face Milling
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IE 262 Class Notes by Figen Eren 1)
Face Milling
#he generated surface is at right angles to the cutter a*is and
is the combined result of actions of the portions of the teethlocated on both periphery and the face of the cutter! Most of
the cutting is done by the peripheral portions of the teeth' with
the face portions providing some finishing actions!
!on"entional #ace milling:
,iameter of tool is larger than wor part;s width!
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8 Partial #ace milling:
8 #he cutter overhangs from one side of wor part !in fig %b&
8 $n milling:
8 Cutters diameter is less than the wor part;s width' so aslot is cut into part! In fig <
IE 262 Class Notes by Figen Eren 16
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IE 262 Class Notes by Figen Eren 1/
Continue!!!
Pro#ile milling:
- form of end milling in which 4utside periphery of flat part is cut!
Poc%et milling:
0imilar to end milling' but the shape created is a shallow pocets in flat
surfaces
S&r#ace conto&ring:
- ball=nose cutter is fed bac and forth across the wor part to create acontoured surface perpendicular to the cutter .
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IE 262 Class Notes by Figen Eren 17
Face milling
Poc%et milling $n milling
Pro#ile milling
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IE 262 Class Notes by Figen Eren 2:
Milling !&tter
#he tool used in milling is nown as a milling cutter ' the cutting edges
called teeth! #ypes of milling cutters are related to the milling operations
can be classified as$
Plain milling c&tter:
+sed in peripheral milling operations
Cylindrical or dis shaped
>ave several straight or helical teeth on periphery +sed to mill flat surfaces
Sie milling c&tter:
0imilar to plain milling cutters
#eeth e*tend radial part way across one or both ends of cylinder toward
the center
elatively narrow
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IE 262 Class Notes by Figen Eren 21
Milling !&tter
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IE 262 Class Notes by Figen Eren 22
More Milling !&tter
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IE 262 Class Notes by Figen Eren 2"
Continue!!!
Form milling c&tter:
i. -nother peripheral milling cutter
= #eeth ground to a special shape to produce a surface having a
desired transverse contour' conve*' concave shape!
and facing narrow surfaces!
i!Concaveii!Conve*
iii!3ear tooth
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8 $n milling c&tter:
8 oos lie a drill bit' but it cuts with
peripheral teeth instead of it;s end! 8 >ave multiple teeth
8 +sed in milling slots' profiling
IE 262 Class Notes by Figen Eren 2(
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IE 262 Class Notes by Figen Eren 2)
Continue!!!Face milling c&tter:
>ave teeth on periphery and both sides
Made of >00
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IE 262 Class Notes by Figen Eren 26
*Slot Milling !&tter
*lot c&tter:
>ave teeth on periphery and both sides +sed for milling the wide groove of a #=slot
In order to use them' a vertical groove must first be made with
a slotting mill or an end mill to provide a clearance for the
shan
#=slot cutter must be fed carefully' because it cuts in ) surfaces
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Fly cutter
IE 262 Class Notes by Figen Eren 2/
•Single-pointed cutting tool with cutting endground to desired shape•Mounted in specialadapter or arbor •Fine feed must be used•Used in experimentalwork instead of aspecially shaped cutter
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-ngular cutter
IE 262 Class Notes by Figen Eren 27
•Teeth neither parallel nor perpendicular to cutting
axis•Used for milling angular surfaces
•Grooes! serrations! chamfers and reamerteeth
•"iided into two groups•Single-angle milling cutters•"ouble-angle milling cutters
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-ngular Cutter
IE 262 Class Notes by Figen Eren 29
•Single-angle•Teeth on angular surface•May or may not hae teeth
on flat•#$% or &'%•"ouble-angle
•Two intersecting angularsurfaces
with cutting teeth on both•()ual angles on both sideof lineat right angle to axis
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Inserted #ooth
IE 262 Class Notes by Figen Eren ":
-nother form of inserted=tooth
cutter consists of round' hardened
steel pins driven into holes in a
cast=iron body! #his cutter is also permanent in form' Fig! 212' as
broen teeth cannot be replaced?
and' when the teeth are worn
almost down to the body' the wholecutter is thrown away
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IE 262 Class Notes by Figen Eren "1
Milling Machine
#he milling machine supplies an accurate rotating spindle
for the cutter and a table %vise& to fi* and position the wor part! #here are two types of machines
+ori,ontal milling machine:
>ori@ontal spindle
,esigned for peripheral milling operations
-ertical milling machine:
Aertical spindle
,esigned for face milling operations
%In our ab!s we have this type of machines&
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IE 262 Class Notes by Figen Eren "2
>ori@ontal Milling Machine
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IE 262 Class Notes by Figen Eren ""
Aertical Milling Machine
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IE 262 Class Notes by Figen Eren "(
!lai#ication o# milling machine
!ol&mn an nee t/pe:
3eneral purpose Column' spindle' cutter' table' nee' base are the common
parts of the vertical and hori@ontal milling machines
In hori@ontal' arbor supports the cutter and an over arm
supports arbor In vertical' milling cutters can be mounted directly in the
spindle
= #he milling machines having only the three mutually
perpendicular table motions %*=y=@ a*es& are called plaincolumn and nee type
=Aertical type is especially well suited for face and end milling
operations
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IE 262 Class Notes by Figen Eren "6
Continue!!!=#wo more special column and nee machines are called
universal and turret type.
Universal type: >as a table that can be rotate in a hori@ontal plane to any
specified angle
Turret type:
>as duel heads that can be rotated about a hori@ontal a*is! #his permits milling to be done hori@ontally' vertically or at any
angle!
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IE 262 Class Notes by Figen Eren "/
#urret #ype Milling Machine
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IE 262 Class Notes by Figen Eren (:
ed #ype Milling Machine%2&
C ti
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IE 262 Class Notes by Figen Eren (1
Continue!!!
Simple':
>as single spindle
Duplex:
>as two spindles' permitting simultaneous milling of two
surfaces at a single pass
Triplex:
>as three spindles' permitting simultaneous milling of three
surfaces at a single pass
Planer t/pe milling machine:
+tili@e several milling heads
Can remove large amount of metal while permitting the table
and wor piece to move Duite slowly
4ften' only single pass is reDuired
= 3ood for heavy pieces
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IE 262 Class Notes by Figen Eren ("
C+##IN3 C4N,I#I4N0 IN MIIN3
#he rotational speed in milling is related to the
desired cutting speed at the surface of the wor piece by eDuation!
N =============
G ,
N rotational speed' revHmin cutting speed' ftHmin %mHmin&
, #ool diameter' ft %m&
C+##IN3 C4N,I#I4N0 IN MIIN3%cont!!1&
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IE 262 Class Notes by Figen Eren ((
% &
#he rotational speed in milling is related to the desired cutting speed at
the surface of the wor piece by eDuation! the feed f r in milling is
usually is given as feed per cutter tooth called chip oad? it represents
the si@e of the chip formed by each cutting edge!
f r N!n t ! f
f r feed rate' inHmin %mmHmin&
f chip load' inHtooth %mmH tooth&
n t number of teeth on cutter
M w! d! f r
d depth of cut' in %mm&
w width of cut' in %mm&
0- MIIN3
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IE 262 Class Notes by Figen Eren ()
0- MIIN3$
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# m ====================
f r
- $ -pproach distance to reach full cutter depth
- √d!%,=d&
# m$ Machining time' min
F-CE MIIN3
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IE 262 Class Notes by Figen Eren (6
F-CE MIIN3$
2!-
# m ====================
f r
- $ -pproach distance to reach full cutter depth
- √w!%,=w&$ For partial Face milling
- ,H2 $ For conventional Face milling
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