This document provides an overview of shaper, milling, and gear cutting machines. It discusses the main components and operations of shaper machines, including the shaper mechanism and work holding devices. It also covers drilling machines, boring operations, and different types of milling machines. Finally, it summarizes gear cutting and generation processes, including gear shaping, planning, and hobbing, as well as methods for finishing gears.

1. UNIT – III
SHAPER, MILLING AND GEAR CUTTING
MACHINES

2. • Shaper
• Types of operations
• Drilling
• Reaming
• Boring
• Tapping
• Milling operations
• Types of milling cutter
• Gear cutting
• Forming and Generation principle
• Construction of gear milling
• Hobbing and Gear shaping processes
• Finishing of gears

3. SHAPER
 The main function of the shaper is to produce flat
surfaces in different planes.
 In general the shaper can produce any surface
composed of straight line elements.
 The shaper was first developed in the year 1836.
 The shaper is a low cost machine tool and is used for
initial rough machining of the blanks.

4. Principle of Machining
• The work is held firmly on the table and the ram
is allowed to reciprocate over it. A single point
cutting tool is attached to the ram. When the
ram moves horizontally in the forward direction,
the tool removes metal from the work. On the
return stroke, metal is not removed. The ram
moves at a slow speed during forward stroke.

5. • But during return stroke, the ram moves at a
faster speed. Though the distances of ram
movement during the forward and return stroke
remain the same, the time taken by the return
stroke is less as it is faster by using Quick return
mechanism.

6. Shaping operation

7. Classification of shaper
1. According to the type of mechanism used
• Crank shaper.
• Geared shaper.
• Hydraulic shaper.
2. According to the position and travel of ram
• Horizontal shaper.
• Vertical shaper.
• Traveling head shaper.

8. 3. According to the type of design of the table
• Standard or plain shaper.
• Universal shaper.
4. According to the type of cutting stroke
• Push type shaper.
• Draw type shaper.

9. SHAPER MACHINE

10. COMPONENTS
• Base
• Column
• Cross rail
• Saddle
• Table
• Ram
• Tool head
• Swivel tool head

11. Tool Head

12. SPECIFICATIONS OF SHAPER MACHINE
• Adjustable stroke
• Length of ram
• Max. and Min. distance from table to ram
• Max. Table travel (Horizontal and vertical)
• Angular movement of table
• Max. Vertical travel of tool slide
• No. of ram speeds and range of speeds
• Range of table feed per stroke of ram
• Overall dimensions (Length. Width, Height)
• Net weight

13. Shaper mechanism (Quick Return Mechanism)
• The shaper machine should be so designed that it can allow the
ram holding the tool to move at a comparatively slower speed
during the forward cutting stroke the cutting speed depending
upon the type of material & machining conditions, whereas
during the return stroke it can allow the ram to move at a faster
rate to reduce the idle return time. This mechanism is known as
Quick return mechanism
1. Crank & slotted link mechanism
2. Whit worth quick return mechanism
3. Hydraulic shaper mechanism

14. Crank & slotted link mechanism
• Since useful work is done only during the forward stroke of
ram, the mechanism driving the ram is so designed that the
return stroke is completed in much less time than the
forward stroke.
• Clearly the time taken to complete forward stroke is
proportional to angle α and the return stroke is completed in
less time which is proportional to angle β.
• The ratio between the cutting time & return time may be
determined by
= [ Cutting time / Return time ] = (α / β)

16. Hydraulic drive quick return mechanism

17. Stroke length Calculation and Adjustment
• The length of the stroke is calculated to be nearly 30
mm longer than the work. The position of stroke is
so adjusted that the tool starts to move from a
distance of 25 mm before the beginning of the cut
and continues to move 5mm after the end of the
cut.
• Forward stroke is the cutting stroke. Return stroke
the tool does not cut,
Double stroke = cutting stroke + return stroke

18. • For example as shown in Fig. 3.7, the length of the work is
100mm. The stroke length of the ram is calculated to be 130
mm. (25+100+5). The calculation of stroke length.

19. Ratchet and Pawl mechanism (Automatic feed mechanism
for the table)

20. Work holding devices
• Work pieces can be held and supported on the
shaper table directly or by having some special
devices. Depending on the size and shape of the
work.
• Shaper vise
• Angle plate
• Clamps and stop pins
• V – Block
• T-bolts and step blocks
• Special fixtures

21. Shaper Vise
• Shaper Vise is the most common and simple
work holding device used in a shaper. Different
types of vises are used in a shaping machine
according to the need.
• Plain vise
• Swivel vise
• Universal vise

22. Shaper vice

23. Clamps and stop pins

24. T-bolts and step blocks

25. Angle plate

26. V – block

27. Types of shaper tools
1. Right hand (R. H) tool
• This is a tool used for machining by moving the
job from right to the left.
2. Left hand (L. H) tool
• This is a tool used for machining by moving the
job from left to right.

28. • Finishing tool
• Goose neck tool
• Slot cutting tool
• T-slot cutting tool
• Form tool

29. Operations performed in a shaping machine
• Different types of operations are performed in a
shaping machine. They are broadly classified as
1. Regular operations ( horizontal, vertical, angle)
2. Special operations (Inclined surface
• Concave surface
• ‘V’ groove
• Deep slot
• Horizontal surface
• Vertical surface
• Step cut surface)

31. Machining a external keyway

32. Machining internal keyway

33. T-slot machining

34. Machining calculations for shaper
1. Cutting speed (v)
= LN (1+m) / 1000
Where
L= length or cutting speed
N speed in rpm
m= ratio between the return and cutting stroke
time

35. Time for machining surface
t = L / (f N) min
Where,
L = length of the stroke,
f = feed per stroke,
N = speed in rpm,

36. Material removal rate (MRR)
• It is the volume of metal removed per unit
time.
MRR = f d L N (1+m) mm3/min
Where
D= is depth of cut in mm
f =is feed in mm/stroke;
N= is strokes/min
L =is length of stroke in mm
M= is ratio of return stroke time to cutting
stroke time

37. DRILLING MACHINE
• Drilling machine is one of the most important
machine tools in a workshop.
• It was designed to produce a cylindrical hole of
required diameter and depth on metal work-
pieces.

38. Types of drilling machines
• Portable drilling machine (or) Hand drilling
machine
• Sensitive drilling machine (or) Bench drilling
machine
• Upright drilling machine
• Radial drilling machine
• Gang drilling machine
• Multiple spindle drilling machine
• Deep hole drilling machine

39. Portable drilling machine
Drills from 12mm to 18 mm diameter.

40. Sensitive Drilling Machine

41. • It is designed for drilling small holes at high
speeds in light jobs.
• It can handle drills up to 15.5mm of diameter.
• The spindle rotates at a speed ranging from 50 to
2000 r.p.m.

42. Upright or Pillar drilling machine
• The upright drilling machine is designed for
handling medium sized work pieces.
• Holes of diameter up to 50 mm can be made with
this type of machine.
1. Round column section upright drilling machine
2. Box column section upright drilling machine

44. Radial drilling machine
• The radial drilling machine is intended for drilling
on medium to large and heavy work pieces.

46. Gang Drilling Machine

47. Specification
 The maximum diameter of the drill
 The size of the largest work piece
 Distance between the face of the column.
 Diameter of the table.
 Maximum travel of the spindle.
 Weight of the machine

48. FEED MECHANISM

49. Operations Performed On Drilling Machine
• Drilling
• Reaming
• Boring
• Counter boring
• Countersinking
• Spot facing
• Tapping
• Lapping
• Grinding
• Trepanning.

50. Drilling
• This is the operation of making a circular hole
by removing a volume of metal from the job
by a rotating cutting tool called drill.

51. Reaming
• This is the operation of re-sizing and finishing
a hole already made by a drill.

52. Boring
• The boring operation where enlarging a hole by
means of adjustable cutting tools with only one
cutting edge.

53. Counter-Boring
• It is the operation of enlarging the end of a hole
cylindrically The tool used is known as counter
bore.

54. Counter-Sinking
• This is the operation of making a cone shaped
enlargement of the end of a hole.

55. Tapping
• It is the operation of cutting internal threads by
using a tool called a tap. A tap is similar to a bolt
with accurate threads cut on it.

56. Drilling tool nomenclature

57. BORING
• Boring is an operation of enlarging and locating
previously drilled holes with a single point
cutting tool.
• The machine used for this purpose is called
boring machine.

59. Horizontal boring machines
• In horizontal boring machine, the tool revolves
and the work is stationary.
• A horizontal boring machine can perform boring,
reaming, turning, threading, facing.
• Work pieces which are heavy, irregular,
unsymmetrical or bulky.

60. Types of horizontal boring machine
• Table type horizontal boring machine
• Planer type horizontal boring machine
• Floor type horizontal boring machine
• Multiple head type horizontal boring
machine
• Vertical boring machines and Turret boring
machine

61. Table type horizontal boring machine
• The work is held stationary on a coordinate work
table having in and out as well as back and forth
movements that is perpendicular and parallel to
the spindle axis.
• This method of boring with longitudinal feed of
the table.

63. Planer type horizontal boring machine
• This machine is similar to the table type
horizontal boring machine except that the work
table has only in and out movements that is
perpendicular to the spindle axis.

65. Floor type horizontal boring machine
• Here, there is no work table and the job is mounted
on a stationary T-slotted floor plate.
• This design is used when large and heavy jobs
cannot be mounted and adjusted on the work
table.
• Horizontal movement perpendicular to the spindle
axis is obtained by traversing the column carrying
the head stock, on guide ways.

67. Multiple head type horizontal boring machine
• The machine resembles a double housing planer
or a Plano-miller and is used for boring holes of
large diameter is mass production.
• The machine may have two, three or four
headstocks. This type of machine may be used
both as a horizontal and vertical machine

69. Vertical boring mill machines

70. VERTICAL TURRET LATHE BORING MACHINE

71. Jig boring machines
• A metal-cutting machine for finishing holes,
planes, and slots with a highly precise
location of centers or surfaces without the use
of special attachments for tool alignment.
• Jig-boring machines are used for boring,
drilling, counter-sinking, reaming.

73. MILLING MACHINE
• Milling is the cutting operation that removes
metal by feeding the work against a rotating
cutter having single or multiple cutting edges.
• A milling machine may also be used for drilling,
slotting, making a circular profile and gear
cutting.

74. MILLING METHODS
• There are two distinct methods of milling
classified as follows:
1. Up-milling or conventional milling, and
2. Down milling or climb milling.

75. Up - Milling or Conventional Milling Procedure
• In the up-milling or conventional milling, the
metal is removed in form of small chips by a
cutter rotating against the direction of travel of
the work piece.
• In this type of milling, the chip thickness is
minimum at the start of the cut and maximum
at the end of cut.

77. Down-Milling or Climb Milling
• In this method, the metal is removed by a
cutter rotating in the same direction of feed of
the work piece.
• Chip thickness is maximum at the start of the
cut and minimum in the end.

79. Specifications of a milling machine
• Number of feeds available (specify their values).
• Number of spindle speeds (specify their values).
• Total power available.
• Spindle nose taper.
• Floor space required.
• Net weight.
• Size (dimensions) of the worktable and its
movement range table

80. Types of milling machine
1. Column and knee type
• Plain or horizontal milling machine.
• Vertical milling machine.
• Universal milling machine.
• Ram type milling machine.
• Omniversal milling machine.
2. Manufacturing or bed type
• Simplex milling machine.
• Duplex milling machine.
• Triplex milling machine.

81. 3. Planer type
4. Special type
• Drum milling machine.
• Rotary table milling machine.
• Profile milling machine.
• Pantograph milling machine.
• Planetary milling machine.

82. Column and Knee Type Milling Machine (Horizontal Milling
Machine)

83. Vertical milling machine

84. Universal milling machine
Vertical – Through Knee
Crosswise – Through saddle
Longitudinal – Table
Angular – Swiveling the Table

85. Omniversal milling machine

86. Simplex milling machine

87. Duplex milling machine

88. Planer type milling machine

89. SPECIAL PURPOSE MILLING MACHINES
1.Rotary table milling machine

90. Drum type milling machine

91. Profile or Contour milling machine

92. Work holding Devices

93. Milling machine attachments
• Vertical milling attachment
• Universal milling attachment
• High speed milling attachment
• Slotting attachment
• Rotary table attachment
• Indexing head attachment

94. MILLING CUTTERS
1. Plain milling cutter
2. Side milling cutter
3. Metal slitting saw
4. Angle milling cutter
5. End milling cutter
6. ‘T’ – Slot milling cutter
7. Fly cutter
8. Formed cutter
9. Woodruff key slot milling cutter

95. Plain milling cutter

96. Side milling cutter

97. Metal slitting saw
THICKNESS OF CUTTER IS 0.5 mm to 5 mm

98. Angle milling cutter

99. T’ – Slot milling cutter

100. End mill
• These cutters are useful in machining long
narrow slots, holes and flat surfaces.

101. Fly cutter

102. FORM MILLING CUTTER

103. Woodruff key slot milling cutter

104. Milling machine operations
• Plain milling
• Face milling
• Straddle milling
• Angular milling
• Gang milling
• Form milling
• End milling
• Keyway milling
• Drilling & reaming
• Boring
• Gear cutting
• Thread milling

105. Plain milling
cutter
WORKPIECE

106. Face milling

107. Angular milling

108. Straddle Milling

109. Gang milling

110. Form Milling

111. End Milling

112. T – Slot milling

113. Gear Milling

114. INDEXING OR DIVIDING HEADS

115. Types of indexing heads
1.Plain or Simple dividing head
2.Universal dividing head
3.Optical dividing head
Methods of indexing
1. Direct indexing
2. Simple or plain indexing
3. Compound indexing
4. Differential indexing
5. Angular Indexing

116. Differential indexing

117. GEAR CUTTING
Two principal methods of gear manufacturing
include
• Gear forming - where the profile of the teeth are
obtained as the replica of the form of the cutting
tool (edge); e.g., milling, broaching etc.
• Gear generation - where the complicated tooth
profile are provided by much simpler form cutting
tool (edges) through rolling type, tool – work
motions, e.g., hobbing, gear shaping etc.

118. Methods of Gear forming
1. Gear cutting by single point form tool
2. Gear cutting by shear speed shaping process
3. Gear milling using a form end mill
4. Gear broaching
5. Template method

119. Gear cutting by single point form tool

120. Gear cutting by shear speed shaping process

121. Gear milling using a form end mill

122. Gear broaching

123. Template method

124. Method of Gear generating processes
1.Gear shaping processes
2.Gear planning processes
3.Gear hobbing processes

125. Gear Cutting by Gear Shaper

127. Gear Shaping by Rack Shaped Cutter (Gear
Planning)

128. Gear Hobbing

130. Finishing of Gear Teeth
• For smooth running, good performance and
long service life, the gears need.
• To be accurate in dimensions and forms
• To have high surface finish and
• To be hard and wear resistive at their tooth
flanks

131. 1. For soft and unhardened gears
• Gear shaving
• Gear rolling or burnishing
2. For hard and hardened gears
• Grinding
• Lapping
3.For soft but precision gears
• Shaving followed by surface hardening and then
lapping

132. Gear shaving
• Gear shaving is a process of finishing of gear
tooth by running it at very high rpm in mesh
with a gear shaving tool.
• A gear shaving tool is of a type of rack or
pinion having hardened teeth provided

134. Gear rolling or burnishing
• In this method the machined gear is rolled
under pressure with three hardened master
gears of high accuracy and finish.
• The machined gear teeth are smeared off by
cold plastic flow, which also helps in
improving the surface of the desired teeth.

136. Gear teeth finishing by lapping
• The lapping process only corrects minute
deviations from the desired gear tooth
profiles.
• The gear to be finished after machining and
heat treatment and even after grinding is run
in mesh with a gear shaped lapping.

137. Gear honing
• It is used for super finishing of the generated gear
teeth.
• In the above gear finishing operations some
operations are based on metal cutting by
removing very small size of chips like gear shaving,
gear grinding, lapping and honing and some other
operations like gear burnishing, roll finishing and
based on finishing by plastic deformation of
metal.