1. UNIT 3
Shaper - Types of operations. Drilling, reaming,
boring, Tapping. Milling operations-types of milling
cutter. Gear cutting – forming and generation principle
and construction of gear milling, hobbing and gear
shaping processes –finishing of gears.
2. SHAPER
Shaper, planner and slotter are used for machining flat surface which
may be horizontal, vertical or inclined surfaces. Single point cutting
tools are mainly used in these machines.
Drilling, grinding, boring, milling and broaching machines are not used
for machining flat surfaces but they are performing specific operations
by using a multi point cutting tool
3. PRINCIPLE OF OPERATION
The shaper having a reciprocating type of machine tool with single
point cutting tool is used to produce flat surfaces.
It has the three important parts such as
Table
Tool head
Ram
4. MACHINING THE VARIOUS TYPE OF
FLAT SURFACES
The table is moved cross wise direction to machine the horizontal
surfaces.
The tool head is moved perpendicular to the table in downward
direction to machine the vertical surfaces.
The tool head is fed at an angle to produce inclined surfaces.
5. CLASSIFICATION OF SHAPER
According to the type of driving mechanism
Crank drive type
Whit worth driving mechanism
Hydraulic drive type
According to the position of ram
Horizontal shaper
Vertical shaper
Travelling head shaper
According to the table design
Plain shaper
Universal shaper
According to the type of cutting stroke
Push out type
Draw cut type
6. PRINCIPLE PARTS OF A SHAPER
The different parts of a shaper are listed
Base
Column
Cross rail
Saddle
Table
Ram
Tool head
9. SHAPER SPECIFICATION
Maximum length of stroke
Maximum crosswise movement of the table
Maximum vertical adjustment of the table
Type of driving mechanism
Power of the motor
Available speed and feed
Type of shaper-plain or universal
Floor space required
Total weight of the shaper
Ratio of cutting stroke time and return stroke time
10. TYPE OF QUICK RETURN MECHANISM
The following are three types of quick return mechanism
Hydraulic drive
Crank and slotted link mechanism
Whit worth quick return mechanism
21. DRILLING
Drilling is the process of producing hole on the work piece by using a
rotating cutter called drill. The machine on which the drilling is carried
out is called drilling machine.
Drilling machine can also used for boring, counter boring, counter
sinking, reaming, tapping and spot facing operations.
22. CLASSIFICATION OF DRILLING MACHINE
Portable drilling machine
Sensitive drilling machine
Bench type
Floor type
Upright drilling machine
Round column type or pillar type
Box column type or square section type
Radial drilling machine
Plain type
Semi-universal type
Universal type
Gang drilling machine
Multiple spindle drilling machine
Automatic drilling machine
Deep hole drilling machine
27. PLAIN TYPE
The following adjustments are available in this type
Vertical movement of the radial arm with respect to the column
Circular movement of the radial arm about the column
Horizontal movement of the tool along the arm ways
28. SEMI UNIVERSAL TYPE
In addition to the above three movements as in the case of plain
type, the fourth movement of the tool post can be swung about a
horizontal axis perpendicular to the arm. This arrangement permits
for drilling a hole inclined at any angle to the horizontal plane
29. UNIVERSAL TYPE
In addition to the above fourth movement as in the case of semi
universal type, the fifth movement of the radial arm is rotated on a
horizontal axis.
All these movements enable the universal drilling machine to drill on a
job at any angle in either horizontal plane or vertical plane or in both
the planes.
30. MULTIPLE SPINDLE DRILLING MACHINE
This machine is more suitable for mass production. In this machine,
several holes of different sizes can simultaneously be drilled. It has
several spindles. They are driven by a single motor by using set of
gears .
All spindles holding the drills are fed into the work at the same time.
The feed is given either by raising the table or lowering the spindle
head.
31. GANG DRILLING MACHINE
When a number of single spindles with essential speed and feed are
mounted side by side on one base and have a common worktable
known as gang drilling machine
32. AUTOMATIC DRILLING MACHINE
A series of drilling machines are arranged to perform more than one
operation at a time in sequence of successive work stations is called
automatic drilling machine.
33. DEEP HOLE DRILLING MACHINE
Deep hole drilling machines are used when the drill hole depth exceeds
the normal drill hole depth.
34. SPECIFICATION OF DRILLING
MACHINE
Maximum size of the drill in mm that the machine can be operated
Table size of maximum dimensions of a job can mount on a table in
square metre.
Maximum spindle travel in mm
The number of spindle speed and range of spindle speeds are in rpm
Power input of the machine is in HP
Floor space required
Net weight of the machine
41. MOUNTING THE DRILL TOOL
Both taper shank and straight shank drills can be mounted on the
drilling machine spindle in a number of ways.
Fitting directly in the spindle
By using a sleeve
By using a socket
By means of chucks
42.
43.
44. BORING
Boring is the process of enlarging and locating previously drilled holes
with a single point cutting tool.
45. TYPE OF BORING MACHINE
Horizontal boring machine
Table type
Floor type
Planer type
Multiple head type
Vertical boring machine
Precision boring machine
Jig boring machine
54. JIG BORING MACHINE
A jig boring machine is a precision boring machine used for boring
accurate holes at centre to centre distances.
There are mainly two types of jig boring machines
Single vertical column type
Planer type
55.
56. MILLING
Milling is the process of removing metal by feeding the work past against
a rotating multipoint cutter. The metal is removed in the form of small
chips.
57. SPECIFICATION OF MILLING
MACHINE
The table length and width
Maximum longitudinal cross and vertical travel of the table
Number of spindle speeds and feeds
Power of driving motor
Floor space required
Type of milling machine
68. WORK HOLDING DEVICES
The following work holding devices are used for clamping the work in
the milling machine.
Swivel vice
Universal vice
Indexing head
69.
70.
71.
72. TOOL HOLDING DEVICES
The following tool holding devices are used in milling machines.
Arbors
Adaptors
Collets
77. According to the type of operation
Plain milling cutter
Side milling cutters
End milling cutters
Angle milling cutters
T slot milling cutter
Slitting saws
Form milling cutter
Fly cutters
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88. MILLING OPERATIONS
Plain or slab milling
Face milling
Angular milling
Straddle milling
Gang milling
Form milling
End milling
T slot milling
Gear cutting
89.
90.
91.
92.
93.
94.
95.
96.
97.
98. DIVIDING HEADS
These are the following types of dividing heads
Plain or simple dividing head
Universal dividing head
Optical dividing head
99.
100.
101.
102. INDEXING METHODS
Direct or rapid indexing
Plain or simple indexing
Differential indexing
Compound indexing
Angular indexing
103. GEAR CUTTING
Gear cutting by single point form tool
Gear cutting by shear speed shaping process
Gear milling using a formed end mill
Gear broaching
Template method
109. GEAR GENERATION PRINCIPLE AND
CONSTRUCTION OF GEAR MILLING
The common gear generation processes are given below
Gear shaping process
Gear planning process
Gear hobbing process
112. APPLICATIONS
Gear shaping is used for generating both internal and external spur
gears.
Helical gears can also be generated using special attachments.
116. FINISHING OF GEARS
Generally the gear teeth are produced by any one of the generating
processes, but the gear does not be more accurate with good quality
surface.
The rough surface gear teeth occur due to vibrations causing noise,
excessive wear, play and backlash between meshing pair of gears.
Therefore, the gear finishing is carried at last in gear manufacturing.