NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
LAB MANUAL
OF
METAL CUTTING
AND
CNC MACHINES
(ME-603)
PREPARED BY:
DEEPANJALI GIRI
ASST. PROFESSOR
MECHANICAL ENGG. DEPTT.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
LIST OF THE EXPERIMENTS
SNO
NAME OF THE EXPERIMENT
1.
Study Of Lathe Machine With Various Operations.
2.
Study Of Types Of Grinding Machine.
3.
Study Of Horizontal And Vertical Milling Machine.
4.
Study Of Radial Drilling Machine.
5.
Study Of Principle Of Broaching Machine.
6.
Study Of Shaper And Quick Return Mechanism.
7.
Study Of Gear Cutting On Milling Machine.
8.
Study Of Gear Cutting Methods.
9.
Study Of Mechatronics.
10.
11
PAGE NO
FROM TO
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO. 1
Object: Study of Lathe Machine with various Operations.
THEORY:
A lathe is a machine tool which turns cylindrical material, touches a cutting tool
to it, and cuts the material. The lathe is one of the machine tools most well used by
machining.
Lathes are machine tools which turn or rotate a lump of material to carry out
various operations like drilling, facing, cutting, threading, reaming, grooving, sanding,
parting, knurling, and boring along with the usage of cutting tools which are applied to
the material to produce an object. The finished product will have symmetry about a
rotational axis. The cutting tool moves parallel or perpendicular with respect to
workpiece axis to create the desired shape. The typical lathe consists of a headstock,
where the spindle is connected to hold the work piece to be machined, gears and speed
changing levers. Opposite end of headstock is the tailstock which is a tool holding device.
The bed is the base of the lathe which is connected with headstock and allows carriage
and tailstock for parallel alignment. A compound rest carries a tool post on which the
toolbit is mounted moves along lead screw as shown in Figure no.1, a material is firmly
fixed to the chuck of a lathe. The lathe is switched on and the chuck is rotated. And since
the table which fixed the byte can be moved in the vertical direction, and the right-andleft direction by operating some handles shown in Fig. 3. It touches a byte's tip into the
material by the operation, and make a mechanical part.
Lathe head stock
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Three Important Elements
In order to get an efficient process and beautiful surface at the lathe machining, it
is important to adjust a rotating speed, a cutting depth and a sending speed. Please note
that the important elements can not decide easily, because these suitable values are quiet
different by materials, size and shapes of the part.
Rotating Speed
It expresses with the number of rotations (rpm) of the chuck of a lathe. When the
rotating speed is high, processing speed becomes quick, and a processing surface is finely
finished. However, since a little operation mistakes may lead to the serious accident, it is
better to set low rotating speed at the first stage.
Fig. 3.Lathe principal
Cutting Depth
The cutting depth of the tool affects to the processing speed and the roughness of
surface. When the cutting depth is big, the processing speed becomes quick, but the
surface temperature becomes high, and it has rough surface. Moreover, a life of byte also
becomes short. If you do not know a suitable cutting depth, it is better to set to small
value.
Sending Speed (Feed)
The sending speed of the tool also affects to the processing speed and the
roughness of surface. When the sending speed is high, the processing speed becomes
quick. When the sending speed is low, the surface is finished beautiful. There are 'manual
sending' which turns and operates a handle, and 'automatic sending' which advances a
byte automatically. A beginner must use the manual sending. Because serious accidents
may be caused, such as touching the rotating chuck around the byte in automatic sending,
Cutting Tools for Lathe
There are various kinds of the cutting tools for a lathe. We must choose them by
the materials and shape of a part. Three typical cutting tools are introduced in follows.
Then we consider what is an easy process or a hard process.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Form of Typical Cutting Tools
Figure 5(a) shows the most well-used cutting tool called a side tool. It can process
to cut an outside surface and an edge surface. Since the material is set at the right of lathe,
then this tool can only cut the right of the material.
The cutting tool shown in Figure 5(b) is used at parting and grooving processes.
Its pointed end is slim, then it is too weak. Don't add a strong side-force to the tool. This
tool must send vertical direction only.
Fig no.5.Types of tools
The cutting tool shown in Figure 5(c) is called a boring bar. It is used to cut at an inside
surface. It can make a big hole, which cannot be process by a drill, and an high accurate
hole.
Advantages
Advantages of lathes are:




Can perform various operations in a single lathe machine
Can be operated along with other machine tools like drill press
Workpieces of larger diameter can be processed in a lathe
Good finishing of materials.
Applications
CNC lathes are widely used lathe machines in most manufacturing industries in order to
perform lathe operations effectively thus reducing productivity time. Other widely used
applications are in automobiles, electrical, electronics, defense, and escalator industries.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO. 2
Object: Study of types of Grinding Machine.
Introduction:
The grinder is a machine that is used for fine surface finishing and the amount of
material removed rarely exceeds a few thousands of an inch. These machines have been
developed over the years to satisfy specific needs of the industry it serves, so grinding has
become specialized, as has turning and milling. The most common types of grinders are
the surface grinder, the universal tool and cutter grinder, and the cylindrical grinder
Surface grinding is probably the most fundamental of operations. Most shops have
a surface grinder even if they don't have a universal cutter grinder of a cylindrical grinder.
The basic machine has grinding wheel above the work area which can be fed downward
in very small increments into a work piece which is being moved to the left and the right
and in and out. This allows the wheel to contact all areas of the surface of the work piece.
The grinder is usually equipped with a magnetic plate used to hold the work piece . It is
sometimes referred to as a magnetic chuck, although it does not look anything like a lathe
chuck . The magnetic chuck holds magnetic materials only. However steel clamps (a
magnetic material) can be used to laterally clamp non-magnetic materials for surface
grinding.
Theory:
The grinding machine consists of a power driven grinding wheel spinning at the
required speed (which is determined by the wheel’s diameter and manufacturer’s rating,
usually by a formula) and a bed with a fixture to guide and hold the work-piece. The
grinding head can be controlled to travel across a fixed work piece or the workpiece can
be moved whilst the grind head stays in a fixed position. Very fine control of the grinding
head or tables position is possible using a vernier calibrated hand wheel, or using the
features of numerical controls.
Grinding machines remove material from the workpiece by abrasion, which can
generate substantial amounts of heat; they therefore incorporate a coolant to cool the
workpiece so that it does not overheat and go outside its tolerance. The coolant also
benefits the machinist as the heat generated may cause burns in some cases. In very highprecision grinding machines (most cylindrical and surface grinders) the final grinding
stages are usually set up so that they remove about 200 nm (less than 1/100000 in) per
pass - this generates so little heat that even with no coolant, the temperature rise is
negligible.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Types:
These machines include the:Belt grinder, which is usually used as a machining
method to process metals and other materials, with the aid of coated abrasives. Sanding is
the machining of wood; grinding is the common name for machining metals. Belt
grinding is a versatile process suitable for all kind of applications like finishing,
deburring, and stock removal.






Bench grinder, which usually has two wheels of different grain sizes for roughing
and finishing operations and is secured to a workbench. It is used for shaping tool
bits or various tools that need to be made or repaired. Bench grinders are
manually operated.
Cylindrical grinder which includes the centerless grinder. A cylindrical grinder
may have multiple grinding wheels. The workpiece is rotated and fed past the
wheel/s to form a cylinder. It is used to make precision rods.
Surface grinder which includes the wash grinder. A surface grinder has a "head"
which is lowered, and the workpiece is moved back and forth past the grinding
wheel on a table that has a permanent magnet for use with magnetic stock.
Surface grinders can be manually operated or have CNC controls.
Tool and cutter grinder and the D-bit grinder. These usually can perform the
minor function of the drill bit grinder, or other specialist toolroom grinding
operations.
Jig grinder, which as the name implies, has a variety of uses when finishing jigs,
dies, and fixtures. Its primary function is in the realm of grinding holes and pins.
It can also be used for complex surface grinding to finish work started on a mill.
Gear grinder, which is usually employed as the final machining process when
manufacturing a high precision gear. The primary function of these machines is to
remove the remaining few thousandths of an inch of material left by other
manufacturing methods (such as gashing or hobbing).
Fig no.1. Grinding operation
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Grinding spindles Characteristics
Some important characteristics common to many grinding spindles are as follows:

In most grinding spindles, there is an oil/air mist lubrication system with an
effective heat dissipation method which helps in simplifying the spindle
configuration.

There is the standard spindle range for vertical grinding and horizontal grinding
which is developed to enable vertical applications and horizontal applications.

There is also spindle range for internal grinding and motorized main spindle
ranges.

Grinding spindles include special solutions to prevent or avoid dirt collection
inside.

The spindle design also considers the different vibration behavior of a rotating
shaft from vertical and horizontal positions etc.
Grinding spindles: Uses
The grinding efficiency is measured in terms of material removal rate which is
attained by employing ultra high wheel speeds. For any ultra high speed grinding
machine tool, the spindle is a key component. The various uses of grinding spindles are
given below:

The grinding spindle is used for roughing and finishing flat, cylindrical and
conical surfaces.

The grinding spindle is used for finishing internal cylinders or bores.

It helps in forming and sharpening cutting tools.

It also helps in snagging or removing rough projections from castings and
stampings.

Another important task of grinding spindles is to cleaning, polishing and buffing
surfaces.
Types of grinding machine spindles
All spindles are usually classified into three main categories-high frequencies,
belt driven or motorized. Other popular types of grinding spindles are:
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING

Internal grinding spindles: Internal grinding is considered to be the most
challenging of all grinding applications. Internal grinding means the precision
grinding of the inside surface of the hole in a work piece, enlarging or finishing of
the cylindrical opening or inside diameter in a workpiece.

External grinding spindles: External grinding, which is also important to many
manufacturing organizations, refers to grinding of the outer surface of a
workpiece.

Horizontal grinding spindles: Horizontal grinding spindles are designed to grind
advanced materials, including wafer backside grinding operations, achieving a
high degree of flatness while at the same time optimizing surface finishes. They
are so called because the grinding process takes place in a horizontal way. On
machines with horizontal spindle the motor-driven spindles are horizontal. In such
machines the parts are guided through the grinding wheels vertically.

Vertical grinding spindles: Vertical grinding , as the name suggests, fixes the
workpiece on a rotary chuck in the machine base , similar to the orientation of the
workpiece on a vertical lathe. The vertical grinding spindle travels up and down
and side to side and at times may also swivel from above the workpiece. On
machines with vertical spindle, the motor-driven spindles are vertical and the
parts are guided through the grinding wheels horizontally.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO. 3
Object: Study of Horizontal and Vertical Milling Machine
Horizontal milling machine:- The main parts of the horizontal mill are the; base,
column, knee, saddle, table, spindle, overarm and arbor supports. Below you will find
illustrations of a horizontal milling machines and it’s parts. Study these parts and be
ready to answer questions concerning their names location and uses.
Column-The column of the milling machine, along with the base, are the major structural
components. They hold, align,
and support the rest of the
machine.
Table-Holds and secures the
workpiece for machining.
Saddle-The saddle is attached
to the knee. The saddle provides
the in and out, or Y axis table
travel.
Knee-The knee supports the
saddle and the table. The knee
can be moved up and down for
workpiece positioning.
Base- The base of the milling
machine, along with the
column, are the major structural
components. They hold, align,
and support the rest of the
machine.
Spindle-The spindle holds
the
tool and provides
the actual tool rotation.
Spindle Reverse Lever-The position of this lever determines the spindle direction. The
three positions of the handle are; In, Middle, and Out. The middle position is the neutral
position. Never move the spindle reverse lever when the spindle is turning.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Spindle Speed Selection Lever-The spindle speed selection lever is used to change the
spindle R.P.M. setting. This type of machine has a geared head so the spindle speed can
only be changed when the spindle is stopped.
Spindle Clutch Lever-The spindle clutch lever engages the spindle clutch to the motor.
By manipulating the spindle clutch lever the operator can start and stop the spindle.
Feed Rate Selection Lever-The feed rate selection lever is used to change the feed rate
setting. The feed rate settings are expressed in inches per minute.
Motor Start and Stop Buttons- The motor start and stop buttons control the power to
the main motor for the machine
Vertical milling machine:
Vertical milling machine. 1: milling cutter 2: spindle 3: top slide or overarm 4:
column 5: table 6: Y-axis slide 7: knee 8: base
In the vertical mill the spindle axis is vertically oriented. Milling cutters are held
in the spindle and rotate on its axis. The spindle can generally be extended (or the table
can be raised/lowered, giving the same effect), allowing plunge cuts and drilling. There
are two subcategories of vertical mills: the bed mill and the turret mill.

A Turret mill has a stationary spindle and the table is moved both perpendicular
and parallel to the spindle axis to accomplish cutting. The most common example
of this type is the Bridgeport, described below. Turret mills often have a quill
which allows the milling cutter to be raised and lowered in a manner similar to a
drill press. This type of machine provides two methods of cutting in the vertical
(Z) direction: by raising or lowering the quill, and by moving the knee.

In the Bed mill, however, the table moves only perpendicular to the spindle's axis,
while the spindle itself moves parallel to its own axis. Turret mills are generally
considered by some to be more versatile of the two designs. However, turret mills
are only practical as long as the machine remains relatively small. As machine
size increases, moving the knee up and down requires considerable effort and it
also becomes difficult to reach the quill feed handle (if equipped). Therefore,
larger milling machines are usually of the bed type.
Also of note is a lighter machine, called a mill-drill. It is quite popular with
hobbyists, due to its small size and lower price. A mill-drill is similar to a small drill
press but equipped with an X-Y table. These are frequently of lower quality than other
types of machines.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Advantages:
There is not much of a difference between horizontal and vertical milling
machines. Both of these equipments are indispensable in cutting parts uniformly and
quickly. These days' horizontal machines are becoming more popular due to its overhead
arm and its arbor driven cutters. These are also very easy to operate with few steps to
remember. Some of the benefits of using horizontal milling machines are discussed
below:
Design and set up: If you are looking to manufacture products which are cost-effective
and of high quality, then a vertical milling machine should be of great help. They have
scientific designs suitable for dealing with various hard materials. The time taken for this
process is minimal and so as the number of steps required operating it. There is no need
for a large set up to install these machines and also no need to employ numerous workers.
You can have substantially savings on the labor cost, which is often the key setback in a
manufacturing environment.Automation and programming: The finished products of
vertical machines are of finer quality, with better finishing. As a result, you get the final
output, just as you would have planned. Majority of the modern horizontal milling
machines are completely automated and requires minimal human intervention. Prior
programming and automation result in minimal errors in production, with 25% less
processing time.Reduced processing time: These equipments perform diverse functions
just like a general machine as well as other activities like tapping and boring. One milling
machine performs these in one operation. Advanced milling also reduces the need for
manual labor significantly, which significantly reduced the operational cost unlike earlier
times. These machines no longer require multiple set ups and change in tools. Horizontal
milling machines are advanced and do not require frequent movement of parts, location
wise. These advancements have reduced delay in processing time drastically.Arm
supports and clutters: Horizontal machines have features of arm supports and clutters,
which are driven by an arbor. These two features help to add value in production. You
should pay attention to reduce incidence of accidents and ensure maximum safety.
Maintenance of cutters is required at a proper interval of time to maintain its sharpness.
Check the location of arm support while they awhile dealing with arbors for maximum
results.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO.4
Object: Study of Radial Drilling Machine.
Theory:
Radial drilling machines are used for drilling medium or large diameter holes up
to 50 mm in heavy work pieces.When it comes to mechanical machining, radial drilling
machine is used for all functions such as drilling, counter boring, spot facing, lapping,
screwing reaming, tapping and boring. Radial drilling machines work well with a variety
of material such as cast iron, steel, plastic etc. Drilling machines hold a certain diameter
of drill (called a chuck) rotates at a specified rpm (revolutions per minute) allowing the
drill to start a hole.Radial drills are of three types. With the plain radial drill, the drill
spindle is always vertical, and may not swing over any point of the work. The spindle in
the half-universal drill may be swung over any point of the work and it may swing in one
plane at any angle to the vertical up to complete reversal of the direction of the drill. And
the spindle in the full-universal drill can be swung in any plane at any angle to the
vertical.
The specialty of radial drilling machine is that they are of robust construction and
are designed for heavy duty drilling. The machines need to have all cast parts of fine
close grained grey iron casting machined to close tolerance. They have to be subject to
rigid inspection at all stages of assembly to ensure accuracy. Superior machines are
known for their Grade 1 accuracy. Radial drilling machines having oil bath gearbox and
hardened gears tend to have a very long life. The rotation and easy sliding of gears in
bearings gives very high reliability. Gears are internally splined and shafts are externally
splined.
The radial drilling machines can have 32 mm 125 mm drilling capacity; mt-4
spindle nose; head stock is bored on toss imported boring machine; double column
grinded by wmw german-make cylindrical grinders; and has 2425 standard accuracy. The
smt 40/1000 dc radial drilling machines are useful in almost every tool room as well as
maintenance purpose.
Our radial drilling machines have heavy-duty high precision all-geared drill head
with forged steel gears and toughened spindle.
Face milling and keyway milling operations is made easy thanks to the
automatic vertical movement of arms as well as horizontal automatic movement of main
spindle head. Accurate inclined drilling is made possible with arm lilting at 360 degrees.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
A lot of time is expended due to the changing of the position of work on a machine. In a
radial drill machine, the drill table is placed on a solid foundation for holding very heavy
work. When a piece of work is secured on the drill table, the drill spindle may be placed
over any part of the work without moving the latter
Construction of Radial Drilling Machine:
The construction details of radial drilling machine are as follows:
The Main Parts of Radial Drilling Machine are:
1. Base:
The base of the machine is a large cast iron material on which is mounted a
cylindrical vertical column. The base is provided with T-slots, which help the workpiece
to be clamped rigidly to the base of the machine.
2. Vertical column:
The column is a long, cylindrical shaped part fastened rigidly to the base. The
column carries a radial arm that can be raised or lowered by means of an electric motor
and can be clamped to any desired position. The radial arm can also be rotated (swiveled)
in a complete circle around the column.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
3. Drill head:
The drill head is mounted on the radial arm and carries a driving motor and a mechanism
for revolving an feeding (power feed) the drill bit into the workpiece. The drill head can
be moved horizontally on the guideways provided in the radial arm, and can be clamped
to any desired position.With the combination of the movements of radial arm the drill
head, it is possible to move the drill bit, and hence generate a hole at any desired position
without moving the workpiece.
Radial Drilling Machine
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO. 5
Object: Study of Principle of Broaching Machine
Theory:
Broaching is the machining process of cutting a shape by moving a broach cutting
tool, usually just called a broach, over material such as metals or plastics. The broach's
rows of teeth, or chisels, progressively increase in size. Each tooth removes the excess
material gradually and the desired shape is complete only after the final broach tooth has
passed through the material.
The shape found in an internal keyway in a pulley or gear is the most common
shape produced by broaching since broaching is the simplest method of cutting internal
forms known as splines on gears, sprockets, and hubs. Polygons such as squares are also
commonly and easily produced by a broach, especially when a round hole needs to be
enlarged into a square or other non-circular shape. Sometimes, broaches are also used to
cut external shapes such as slots.
Interestingly, due to the effectiveness of their original concept and design, today's
broaching machines and processes have remained mostly the same since the start of the
Industrial Revolution. No job is too large or too small for a broach. Numerous materials
such as both ferrous and nonferrous metals as well as many types of plastics are suitable
for broaching.
Broaching tools fall under the classification of multiple-point cutting tools as they
have at least two cutting edges. Broaches can be custom made from blueprints, but stock
broaches are often readily available in numerous lengths and sizes. Common broach
shapes include square, round, oval, keyway, serration, D, spline, and pot broaches.
Typically, broaches are made from top quality tool steel such as PM-M4
Fig. no.1 broaching tools
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Besides the broach cutting tool itself, fixtures that support the broach are also
needed in broaching operations. For example, in keyway broaching, a fixture called a
broach horn supports the broach in a shared circular hole.
All broaching operations require proper alignment of the broach and its
supportive tooling. Improper alignment will result in cuts that are not perfectly straight.
Misalignment can even cause broach breakage. Lubrication is often used in broaching in
order to reduce friction, either by applying cutting oil to the material to be cut, or by
lubricating the backs of the cutting broaches, depending on the types of broaches and the
broaching materials being used.
Types of broaches :
Fig.no.2.Types of Broach
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Broaches can be categorized by many means:





Use: internal, or surface
Purpose: single, or combination
Motion: push, pull, or stationary
Construction: solid, built-up, hollow or shell
Function: roughing, sizing, or burnishing
If the broach is large enough the costs can be reduced by using a built-up or modular
construction. This involves producing the broach in pieces and assembling it. If any
portion wears out only that section has to be replaced, instead of the entire broach. Most
broaches are made from high speed steel (HSS) or an alloy steel; Tin coatings are
common on HSS to prolong life. Except when broaching cast iron, tungsten carbide is
rarely used as a tooth material because the cutting edge will crack on the first pass
Surface broaches:
The slab broach is the simplest surface broach. It is a general purpose tool for cutting flat
surfaces.
Slot broaches (G & H) are for cutting slots of various dimensions at high
production rates. Slot broaching is much quicker than milling when more than one slot
needs to be machined, because multiple broaches can be run through the part at the same
time on the same broaching machine.
Contour broaches are designed to cut concave, convex, cam-, contoured, and
irregular shaped surfaces.
Pot broaches are cut the inverse of an internal broach; they cut the outside
diameter of a cylindrical workpiece. They are named after the pot looking fixture in
which the broaches are mounted; the fixture is often referred to as a "pot". The pot is
designed to hold multiple broaching tools concentrically over its entire length. The
broach is held stationary while the workpiece is pushed or pulled through it. This has
replaced hobbing for some involute gears and cutting external splines and slots.
Straddle broaches use two slab broaches to cut parallel surfaces on opposite sides
of a workpiece in one pass. This type of broaching holds closer tolerances than if the two
cuts were done independently. It is named after the fact that the broaches "straddle" the
workpiece on multiple sides
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Internal broaches
A modular broach
Solid broaches are the most common type; they are made from one solid piece of
material. For broaches that wear out quickly shell broaches are used; these broaches are
similar to a solid broach, except there is a hole through the center where it mounts on an
arbor. Shell broaches cost more initially, but save cost overall if the broach must be
replaced often because the pilots are on the mandrel and do not have to be reproduced
with each replacement.
Modular broaches are commonly used for large internal broaching applications.
They are similar to shell broaches in that they are a multi-piece construction. This design
is used because it is cheaper to build and resharpen and is more flexible than a solid
design.
A common type of internal broach is the keyway broach (C & D). It uses a special
fixture called a horn to support the broach and properly locate the part with relations to
the broach.
A concentricity broach is a special type of spline cutting broach which cuts both
the minor diameter and the spline form to ensure precise concentricity.
The cut-and-recut broach is used to cut thin-walled workpieces. Thin-walled
workpieces have a tendency to expand during cutting and then shrink afterward. This
broach overcomes that problem by first broaching with the standard roughing teeth,
followed by a "breathing" section, which serves as a pilot as the workpiece shrinks. The
teeth after the "breathing" section then include roughing, semi-finishing, and finishing
teeth

An internal broach for cutting splines
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING

The finishing teeth

The semi-finishing teeth

The roughing teeth

The front pilot

NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
SPECIAL-BROACHES:
New England Broach engineering has enabled manufacturers to machine
parts of unusual size or shape. In each case, the application of the "special"
broach has resulted in increased production, reduced down time, and
improved product quality on both long and short runs.
ADVANTAGES OF BROACHING:
•Produces parts at a high rate.
•Removes heavy amounts of stock.
•Roughs and finishes in one pass.
•Permits the machining of complex contours and simple shapes.
•Economical operation.
The cost per finished part is lower because of the high production rates
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO.6
Object: Study of Shaper and Quick Return Mechanism.
Theory:
A shaper is a type of Machine tool that uses linear relative motion between the
workpiece and a single-point cutting tool to machine a linear toolpath. Its cut is
analogous to that of a lathe, except that it is (archetypally) linear instead of helical.
(Adding axes of motion can yield helical toolpaths, as also done in helical planing.) A
shaper is analogous to a planer, but smaller, and with the cutter riding a ram that moves
above a stationary workpiece, rather than the entire workpiece moving beneath the cutter.
The ram is moved back and forth typically by a crank inside the column; hydraulically
actuated shapers also exist
Types:
Shapers are mainly classified as standard, draw-cut, horizontal, universal, vertical,
geared, crank, hydraulic, contour and traveling head.[1] The horizontal arrangement is the
most common. Vertical shapers are generally fitted with a rotary table to enable curved
surfaces to be machined (same idea as in helical planing). The vertical shaper is
essentially the same thing as a slotter (slotting machine), although technically a
distinction can be made if one defines a true vertical shaper as a machine whose slide can
be moved from the vertical. A slotter is fixed in the vertical plane.Small shapers have
been successfully made to operate by hand power. As size increases, the mass of the
machine and its power requirements increase, and it becomes necessary to use a motor or
other supply of mechanical power. This motor drives a mechanical arrangement (using a
pinion gear, bull gear, and crank, or a chain over sprockets) or a hydraulic motor that
supplies the necessary movement via hydraulic cylinders.
Operation:
Shaper linkage. Note the drive arm revolves less for the return stroke than for the cutting
stroke, resulting in a quicker return stroke and more powerful cutting stroke. A shaper
operates by moving a hardened cutting tool backwards and forwards across the
workpiece. On the return stroke of the ram the tool is lifted clear of the workpiece,
reducing the cutting action to one direction only. The work piece mounts on a rigid, boxshaped table in front of the machine. The height of the table can be adjusted to suit this
workpiece, and the table can traverse sideways underneath the reciprocating tool, which
is mounted on the ram. Table motion may be controlled manually, but is usually
advanced by automatic feed mechanism acting on the feedscrew. The ram slides back and
forth above the work. At the front end of the ram is a vertical tool slide that may be
adjusted to either side of the vertical plane along the stroke axis. This tool-slide holds the
clapper box and tool post, from which the tool can be positioned to cut a straight, flat
surface on the top of the workpiece. The tool-slide permits feeding the tool downwards to
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
deepen a cut. This adjustability, coupled with the use of specialized cutters and tool
holders, enable the operator to cut internal and external gear tooth profiles, splines,
dovetails, and keyways.The ram is adjustable for stroke and, due to the geometry of the
linkage, it moves faster on the return (non-cutting) stroke than on the forward, cutting
stroke. This action is via a slotted link or Whitworth link.
Uses:
The most common use is to machine straight, flat surfaces, but with ingenuity and
some accessories a wide range of work can be done. Other examples of its use are:
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Keyways in the boss of a pulley or gear can be machined without resorting to a
dedicated broaching setup.
Dovetail slides
Internal splines
Keyway cutting in blind holes
Cam drums with toolpaths of the type that in CNC milling terms would require 4or 5-axis contouring or turn-mill cylindrical interpolation
It is even possible to obviate wire EDM work in some cases. Starting from a
drilled or cored hole, a shaper with a boring-bar type tool can cut internal features
that don't lend themselves to milling or boring (such as irregularly shaped holes
with tight corners).
Shaper drive mechanisms:
A shaper drive mechanism changes the rotary motion of the power source (Electric
motor) into the reciprocating motion of the ram.Metal cutting is carried out during the
forward stroke of the ram only; the return stroke of the ram does no cutting and hence is
called idle stroke. Since return stroke does no cutting the drive system incorporates a
quick return mechanism so that the ram moves faster during return stroke in order to
minimize the idle time. The two common mechanism used for this purpose are,
a) Crank and slotted link quick return mechanism
b) Whitworth quick return mechanism
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
a) Crank and slotted link mechanism
The crank and slotted link quick return mechanism is shown in figure. Slotted link
mechanism is very common in mechanical shapers. This is a simple and compact
mechanism. It converts the rotary motion of the electric motor and gear box into the
reciprocating motion of the ram. The slotted link mechanism gives the ram a higher
velocity during the return non-cutting stroke that during its forward cutting stroke.
Thereby the time wasted during the return stroke is reduced.
The bull gear (Fig. a) is driven by a pinion which is connected to the motor shaft
through a multi speed gear box. The bull wheel is provided with a slot (Fig b). The crank
pin ‘A’ is secured into this slot; simultaneously it can slide in the slotted crank ‘B’. When
the bull wheel rotates the crank pin ‘A’ also rotates and side by side slides through the
slot in the slotted crank ‘B’. This makes the slotted crank to oscillate about its one end C.
This oscillating motion of the slotted crank makes the ram to reciprocate. The
intermediate link D is necessary to accommodate the rise and fall of the crank.
The position of the crank pin ‘A’ in the slot in the bull wheel decides the length of
the stroke of the shaper. The further it is away from the centre of bull wheel, the longer is
the stroke. The cutting stroke of the ram is completed while the crank pin moves from A
to Al and the slotted crank goes from left to right. Similarly during the return stroke crank
pin moves from Al to A and the link changes its position from right to left.
The time taken by cutting and idle strokes of the ram is proportional to the angles
AZA1 and A1ZA respectively.
Cutting time =
angle
LAZA1
Idle time
angle
LA1ZA
=
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Since the crank pin ‘A’ rotates with uniform velocity and angle LA1ZA is smaller it is
obvious that the idle stroke is quicker than the forward cutting stroke. Hence the crank
and slotted link mechanism is known as quick return mechanism.
b) Whitworth Quick Return Mechanism:
Whitworth quick return mechanism is shown in figure. Crank BC revolves at a
uniform speed. During cutting stroke the point ‘C travels from Y to X through Z. The ram
is returned at high speed as the crank rotates from X to Y though ‘T’
Then Time for cutting stroke/ Time for return stroke
= 360- 6/6
Since 0 is smaller than 360-0, the time for cutting is more than the idle stroke time.
Hence it is known as quick return motion. The stroke length can be changed by varying
the radius AE. Since the change in stroke length alters the cutting speed it requires a
change of gear to get desired cutting speed.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO. 7
Object: Study of Gear Cutting on Milling Machine
THEORY:
The gear blank is mounted on a mandrel which is supported between the center of
the dividing head and one more center at the other end, as shown in fig. At a time one
tooth space is cut by the milling cutter, and a dividing head is used to index the job to the
next required tooth space. The cutter is chosen according to the module (or DP) and
number of teeth of the gear to the cut. This cutter is mounted on the milling arbor. Before
the gear can be cut, it is necessary to have the cutter centered accurately relative to the
gear holding mandrel. One way is to adjust the machine table vertically and horizontally
until one corner of the cutter just touches the mandrel on one side. Both the dials (of the
table and the knee) are then set to zero. The table is then adjusted for the cutter to just
touch on the other side of the mandrel with vertical dial showing zero. The reading of the
horizontal feed screw is read. This reading divided by two gives the central position of
the mandrel relative to the cutter. When the table is set centrally in this manner it should
be locked in that position. The table is then fed vertically so that the blank just touches
the cutter. The vertical dial is then set to zero. This is required to give the depth of cut on
thejob.
With these settings the machine can be started and traversed along the axis of the
job to cut the tooth over the whole width of the gear. Depth is increased slowly until it
reaches the full depth of the tooth. With the depth setting the backlash of the gear can be
controlled suitably. After one tooth space is cut, the blank is indexed through 1/z
revolution by means of the dividing head, and the process is repeated until all the teeth
are cut.
Fig no.1. Gear cutting on milling
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO. 8
Object: Study of Gear Cutting methods
THEORY:
Gear cutting is the process of creating a gear. The most common processes
include hobbing, broaching, and machining; other processes include shaping, forging,
extruding, casting, and powder metallurgy. Gears are commonly made from metal,
plastic, and wood.
Broaching Processes:
Broaching is a machining process that uses a toothed tool, called a broach, to
remove material. There are two main types of broaching: linear and rotary. In linear
broaching, which is the more common process, the broach is run linearly against a
surface of the workpiece to effect the cut. Linear broaches are used in a broaching
machine, which is also sometimes shortened to broach. In rotary broaching, the broach is
rotated and pressed into the workpiece to cut an axis symmetric shape. A rotary broach is
used in a lathe or screw machine. In both processes the cut is performed in one pass of
the broach, which makes it very efficient.Broaching is used when precision machining is
required, especially for odd shapes. Commonly machined surfaces include circular and
non-circular holes, splines, keyways, and flat surfaces. Typical workpieces include small
to medium sized castings, forgings, screw machine parts, and stampings. Even though
broaches can be expensive, broaching is usually favored over other processes when used
for high-quantity production runs. Broaches are shaped similar to a saw, except the teeth
height increases over the length of the tool. Moreover, the broach contains three distinct
sections: one for roughing, another for semi-finishing, and the final one for finishing.
Broaching is an unusual machining process because it has the feed built into the tool. The
profile of the machined surface is always the inverse of the profile of the broach. The rise
per tooth (RPT), also known as the step or feed per tooth, determines the amount of
material removed and the size of the chip. The broach can be moved relative to the
workpiece or vice-versa. Because all of the features are built into the broach no complex
motion or skilled labor is required to use it. A broach is effectively a collection of singlepoint cutting tools arrayed in sequence, cutting one after the other; its cut is analogous to
multiple passes of a shaper.For very large gears or splines, a vertical broach is used. It
consists of a vertical rail that carries a single tooth cutter formed to create the tooth shape.
A rotary table and a Y axis are the customary axes available. Some machines will cut to a
depth on the Y axis and index the rotary table automatically. The largest gears are
produced on these machines.Other operations such as broaching work particularly well
for cutting teeth on the inside. The downside to this is that it is expensive and different
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
broaches are required to make different sized gears. Therefore it is mostly used in very
high production runs.
Hobbing
Hobbing is a machining process for making gears, splines, and sprockets on a
hobbing machine, which is a special type of milling machine. The teeth or splines are
progressively cut into the workpiece by a series of cuts made by a cutting tool called a
hob. Compared to other gear forming processes it is relatively inexpensive but still quite
accurate, thus it is used for a broad range of parts and quantities.
It is the most widely used gear cutting process for creating spur and helical gears and
more gears are cut by hobbing than any other process since it is relatively quick and
inexpensive.
Hobbing is a method by which a hob is used to cut teeth into a blank. The cutter
and gear blank are rotated at the same time to transfer the profile of the hob onto the gear
blank. The hob must make one revolution to create each tooth of the gear. Used very
often for all sizes of production runs, but works best for medium to high.
Machining
Conventional machining, one of the most important material removal methods, is
a collection of material-working processes in which power-driven machine tools, such as
saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to
mechanically cut the material to achieve the desired geometry. Machining is a part of the
manufacture of almost all metal products, and it is common for other materials, such as
wood and plastic, to be machined. A person who specializes in machining is called a
machinist. A room, building, or company where machining is done is called a machine
shop. Much of modern day machining is controlled by computers using computer
numerical control (CNC) machining. Machining can be a business, a hobby, or both.
The precise meaning of the term "machining" has evolved over the past 1.5 centuries as
technology has advanced. During the Machine Age, it referred to (what we today might
call) the "traditional" machining processes, such as turning, boring, drilling, milling,
broaching, sawing, shaping, planing, reaming, and tapping, or sometimes to grinding.
Since the advent of new technologies such as electrical discharge machining,
electrochemical machining, electron beam machining, photochemical machining, and
ultrasonic machining, the retronym "conventional machining" can be used to differentiate
the classic technologies from the newer ones. The term "machining" without qualification
usually implies conventional machining.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Spur may be cut or ground on a milling machine or jig grinder utilizing a numbered gear
cutter, and any indexing head or rotary table. The number of the gear cutter is determined
by the tooth count of the gear to be cut.
To machine a helical gear on a manual machine, a true indexing fixture must be used.
Indexing fixtures can disengage the drive worm, and be attached via an external gear
train to the machine table's handle (like a power feed). It then operates similarly to a
carriage on a lathe. As the table moves on the X axis, the fixture will rotate in a fixed
ratio with the table. The indexing fixture itself receives its name from the original
purpose of the tool: moving the table in precise, fixed increments. If the indexing worm is
not disengaged from the table, one can move the table in a highly controlled fashion via
the indexing plate to produce linear movement of great precision (such as a vernier
scale).
There are a few different types of cutters used when creating gears. One is a rack shaper.
These are straight and move in a direction tangent to the gear, while the gear is fixed.
They have six to twelve teeth and eventually have to be moved back to the starting point
to begin another cut.
A popular way to build gears is by form cutting. This is done by taking a blank gear and
rotating a cutter, with the desired tooth pattern, around its periphery. This ensures that the
gear will fit when the operation is finished.
Shaping
A gear shaper is a machine tool for cutting the teeth of internal or external gears. The
name shaper relates to the fact that the cutter engages the part on the forward stroke and
pulls away from the part on the return stroke, just like the clapper box on a planer shaper.
The cutting tool is also gear shaped having the same pitch as the gear to be cut. However
number of cutting teeth must be less than that of the gear to be cut for internal gears. For
external gears the number of teeth on the cutter is limited only by the size of the shaping
machine.
For larger gears the blank is usually gashed to the rough shape to make shaping easier
The old method of gear cutting is mounting a gear blank in a shaper and using a tool
shaped in the profile of the tooth to be cut. This method also works for cutting internal
splines.
Another is a pinion-shaped cutter that is used in a gear shaper machine. It is basically
when a cutter that looks similar to a gear cuts a gear blank. The cutter and the blank must
have a rotating axis parallel to each other. This process works well for low and high
production run
.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
EXPERIMENT NO.9
Object: Study of Mechatronics
Theory:
Mechatronics is the combination of Mechanical engineering, Electronic
engineering, Computer engineering, Control engineering, and Systems Design
engineering in order to design, and manufacture useful products. Mechatronics is a
multidisciplinary engineering system design, that is to say it rejects splitting engineering
into separate disciplines.
A mechatronics engineer unites the principles of mechanics, electronics, and
computing to generate a simpler, more economical and reliable system. Mechatronics is
centered on mechanics, electronics, computing, control engineering, molecular
engineering (from nanochemistry and biology), and optical engineering, which,
combined, make possible the generation of simpler, more economical, reliable and
versatile systems. The portmanteau "mechatronics" was coined by Tetsuro Mori, the
senior engineer of the Japanese company Yaskawa in 1969. An industrial robot is a prime
example of a mechatronics system; it includes aspects of electronics, mechanics, and
computing to do its day-to-day jobs.
Engineering cybernetics deals with the question of control engineering of
mechatronic systems. It is used to control or regulate such a system (see control theory).
Through collaboration, the mechatronic modules perform the production goals and inherit
flexible and agile manufacturing properties in the production scheme. Modern production
equipment consists of mechatronic modules that are integrated according to a control
architecture. The most known architectures involve hierarchy, polyarchy, heterarchy, and
hybrid. The methods for achieving a technical effect are described by control algorithms,
which might or might not utilize formal methods in their design. Hybrid systems
important to mechatronics include production systems, synergy drives, planetary
exploration rovers, automotive subsystems such as anti-lock braking systems and spinassist, and every-day equipment such as auto focus cameras, video, hard disks, and CD
players.
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
Application:
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Machine vision
Automation and robotics
Servo-mechanics
Sensing and control systems
Automotive engineering, automotive equipment in the design of subsystems such
as anti-lock braking systems
Computer-machine controls, such as computer driven machines like IE CNC
milling machines
Expert systems
Industrial goods
Consumer products
Mechatronics systems
Medical mechatronics, medical imaging systems
Structural dynamic systems
Transportation and vehicular systems
Mechatronics as the new language of the automobile
Diagnostic, reliability, and control system techniques
Computer aided and integrated manufacturing systems
Computer-aided design
Engineering and manufacturing systems
Packaging
Physical implementations:
For most mechatronic systems, the main issue is no more how to implement a control
system, but how to implement actuators and what is the energy source. Within the
NAME OF LABORATORY: METAL CUTTING & CNC
LAB SUBJECT CODE: ME-603
NAME OF DEPARTMENT: MECHANICAL ENGINEERING
mechatronic field, mainly two technologies are used to produce the movement: the piezoelectric actuators and motors, or the electromagnetic actuators and motors. Maybe the
most famous mechatronics systems are the well known camera autofocus system or
camera anti-shake systems.
Concerning the energy sources, most of the applications use batteries. But a new trend is
arriving and is the energy harvesting, allowing transforming into electricity mechanical
energy from shock, vibration, or thermal energy from thermal variation, and so on.
Variant of the field:
An emerging variant of this field is biomechatronics, whose purpose is to integrate
mechanical parts with a human being, usually in the form of removable gadgets such as
an exoskeleton. Such an entity is often identified in science fiction as a cyborg. This is
the "real-life" version of cyberware.
Another emerging variant is Electronical or electronics design centric ECAD/MCAD
co-design. Electronical is where the integration and co-design between the design team
and design tools of an electronics centric system and the design team and design tools of
that systems physical/mechanical enclosure takes place.
Disadvantages:
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different expertise required
more complex safety issues
increase in component failures
increased power requirements
lifetimes change/vary
real-time calculations/mathematical models.