Industrial Training on Production ShopIndustrial Training on Production Shop
I, Ashutosh Kumar Mishra, studying in 7 semester of Bachelor of
Technology in Mechanical Engineering at IIMT College Of Engineering,
Greater Noida, hereby declared that this project entitled “Industrial
Training on Production Shop” which is being submitted by me under the
guidance of Prof. Dr Devraj kr Tiwari and Prof. KP Singh, Department Of
Mechanical Engineering, IIMT College Of Engineering, Greater Noida.
I further undertake that the matter embodied in the dissertation
has not been submitted previously for the Industrial Training.
Place :- Greater Noida Ashutosh Kumar Mishra
At the end of this module, I am able to:At the end of this module, I am able to:
Apply and practice workshop safetyApply and practice workshop safety
regulations during working in CNC workshop.regulations during working in CNC workshop.
Apply the concept of CNC metal cuttingApply the concept of CNC metal cutting
operation correctly in milling process.operation correctly in milling process.
Carry out CNC mill machining proceduresCarry out CNC mill machining procedures
Utilize the important parameters in CNCUtilize the important parameters in CNC millmill
machining operation effectively according tomachining operation effectively according to
a given task.a given task.
Milling is a cutting operation with a geometrically
specified cutting edge in which the tool makes the
rotating main movement, and the feed as well as
the infeed movement are generally made by the
Milling operations are classified according to the
position of the milling axis towards the work part,
i.e. between face milling and peripheral milling. In
case of face milling, the milling axis is located
vertically to the machining.
The work part surface is machined by the main
cutting edges. Also, the work part surface is further
finished with auxiliary cutting edges.
synchronous and conventional milling (Figure
1.4 and 1.5) are differentiated.
In case of conventional milling the rotation
direction of the milling tool is opposite to the
feed direction of the work part.
The milling tool chamfer edge starts with chip
The milling tool cutting edge slides in front of
the chip chamfer edge until the required
minimum chip thickness has been achieved
for chip building.
For synchronous milling the rotation direction
of the milling tool and the feed movement of
the work part are parallel.
The tooth of the milling cutter immediately
penetrates into the work part.
Since the milling tool cutting edge is exposed to
impact forces the feed drive needs to be play
free. Several cutters should always be in
The surface quality is flatter and duller when
synchronous milling is used.
Compared with conventional milling higher
feed movements and cutting speeds within the
same cutting edge life can be achieved.
1.3.1 Characteristics of CNC Milling
Work part machining on CNC machine tools
requires controllable and adjustable infeed
axes which are run by the servo motors
independent of each other.
CNC- milling machines (Figure 1.7) on the
other hand have at least 3 controllable or
adjustable feed axes marked as X, Y, Z.
Figure 2.7 : Controllable NC Axes on a Milling Machine
a) Coordinate Systems On CNC Machine
Coordinate systems enable the exact
description of all points on a work plane
or room. Basically there are two types
of coordinate systems
A Cartesian coordinate system, also
called rectangular coordinate system
includes for the exact description of the
› Two coordinate axes (two-dimensional
Cartesian coordinate system) or also.
› Three coordinate axes (three-dimensional
Cartesian coordinate system), located
vertically to each other
In the Cartesian coordinate system a point is
described, for instance, by its X and Y coordinates.
For rotation symmetrical contours, such as circular
boring patterns, calculating the needed
coordinates requires extensive computing.
In the polar coordinate system a point is specified
by its distance (radius r) to the point of origin and its
angle (α) to a specified axis. The angle (α) refers to
the X axis in the X,Y coordinate system.
The angle is positive, if it is measured
counterclockwise starting from the positive X axis
The specifications of the three axes as well as the three
coordinates are done as a so-called clockwise-rotating system
and follow the right-hand-rule (Figure 1.10). The fingers of the
right hand always show to the positive direction of each axis.
This system is also called the clockwise-rotating coordinate
Figure 1.10 : Right-Hand-Rule
Machine Coordinate System
› The machine coordinate system of the CNC machine tool
is defined by the manufacturer and cannot be changed.
› The point of origin for this machine coordinate system,
also called machine zero point M, cannot be shifted in its
Work Part Coordinate System
› The work part coordinate system is defined by the
programmer and can be changed. The location of the
point of origin for the work part coordinate system, also
called work part zero point W, can be specified as
Figure 2.11 : Machine Coordinate System Figure 2.12 : Work Part Coordinate System
The design of the CNC machine specifies the
definition of the respective coordinate
Correspondingly, the Z axis is specified as the
working spindle (tool carrier) in CNC milling
machines (Figure 1.13), whereby the positive
Z direction runs from the work part upwards
to the tool.
The X axis and the Y axis are usually parallel
to the clamping plane of the work part.
When standing in front of the machine, the
positive X direction runs to the right and the Y
axis is away from the viewer.
The zero point of the coordinate system is
recommended to be placed on the outer
edge of the work part.
Figure 1.13 : Milling Part In Three-Dimensional Cartesian Coordinate System
a) Types of Zero And Reference Points
Table 1.1 : Types of zero and references points
Each numerically controlled machine tool works with
a machine coordinate system.
The machine zero point is the origin of the machine-
referenced coordinate system.
It is specified by the machine manufacturer and its
position cannot be changed.
In general, the machine zero point M is located in the
center of the work spindle nose for CNC lathes and
above the left corner edge of the work part carrier
for CNC vertical milling machines.
A machine tool with an incremental travel
path measuring system needs a calibration
point which also serves for controlling the
tool and work part movements.
This calibration point is called the reference
point R. Its location is set exactly by a limit
switch on each travel axis.
The coordinates of the reference point, with
reference to the machine zero point, always
have the same value. This value has a set
adjustment in the CNC control.
Figure 1.14 : Location Of The Zero And Reference Point For Milling
a) Structure of an NC-Block (Format)
› Unlike the conventional milling machine, a
modern machine tool will be equipped with a
numerical control system. The machining of a
work part can be executed automatically,
provided that each machining cycle has been
described in a "language" (code) which can be
read by the control system.
› The total of coded descriptions relating to a
work part is called an NC-program.
› Each NC-program consists of a number of so-called
blocks, which contain the commands to be
executed. The blocks are consecutively numbered;
each block number consisting of a letter "N" plus a
(e.g. three-digit) numeral. Block numbers appear at
the beginning of each program line
* Words Address, Value
› As a rule an NC block is comprised of several words.
Each word consists of an address (letter) and a
value or code (numerals).
A numeral can either represent a code (e.g. G01:
Linear feed motion) or a real value (e.g. X+60 :
Approaching the target coordinate X=60).
Example of part program:
N110 F95 S850 M03
N115 G00 X+25 Y+30
N120 G01 Z-8
N110 A feed rate of 95 mm/min and a spindle speed of
850 U/min is programmed.
N115 The tool is moved in the rapid traverse motion
from its current position to the starting point
N120 Infeed in the Z-axis at the programmed feed rate
N125 Because G01 is a modal command, the tool will
continue to move at the programmed feed rate on a
straight line to the target position X=105
N130 The tool moves in the Y-axis to the target position
The technology data programmed in block N110
(feed rate, speed and sense of cutter rotation) will be
retentive and take effect through blocks N120 to
G00 Rapid move G0 X# Y# Z# up to 6 axis or G0 Z# X#
G01 Linear feedrate move G1 X# Y# Z# up to 6 axis or
G1 Z# X#
G02 Clockwise move
G03 Counter clockwise move
G04 Dwell time
G08 Spline smoothing on, optional L# number of
blocks to buffer
G09 Exact stop check, spline smoothing Off
G10 Linear feedrate move with decelerated stop
G11 Controlled Decel stop
G17 X Y Plane
G18 X Z Plane
G19 Y Z Plane
G28 move to position relative to machine zero
G53 Cancel fixture coordinate offsets
G54-G59 fixture coordinate offsets 1 through 6
G70 Inch mode
G71 Millimeter mode
G80 Cancels canned cycles and modal cycles
G81 Drill cycle
G82 Dwell cycle
G83 Peck cycle
G84 Tapping cycle
G85 Boring cycle 1 bore down, feed out
G86 Boring cycle 2 bore down, dwell, feed out
G88 Boring cycle 3 bore down, spindle stop, dwell,
G89 Boring cycle 4 bore down, spindle stop, dwell,
G90 Absolute mode
G91 Incremental mode
G92 Home coordinate reset
G93 cancel home offsets
G98 - G199 User-definable G codes
With each NC-block a number of additional functions (M-
Functions) can be programmed, such as machine functions
and switches, e.g. to specify the feed rate, the spindle speed
and the tool change.
List of M Codes
Feed Rate, F
The feed rate is programmed in millimeters per
minute (mm/min). Example: F080.000; Here the
programmed feed rate is 80 millimeters per minute.
Spindle Speed, S
The spindle speed is programmed in revolutions per
minute (RPM). Example: S500; Here the
programmed spindle speed is 500 revolutions per
Tool Change, T
A tool change is programmed by a four-digit
number at the address T. The first two positions of
that number indicate the tool position in the
magazine; the last two positions indicate the tool
Example: T0808; This command effect the loading
of the tool to position No.8 of the current tool
magazine and the reading-in of the corresponding
compensation value storage No.8.
In the CNC Simulator there is a maximum
of 99 magazine positions available, as well
as 99 compensation value registers. This
provides the opportunity, for example, to
assign the compensation value register
No. 36 to the tool in the magazine position
No. 12). The applicable NC-command
would then be programmed as follows:
The following clamping variations can be
distinguished for milling machine.
› Jaw Chucking
› Magnetic Chucking
› Modular Chucking
The milling cutter machine table with its T-slots is the
basis for work part clamping. Depending on how the
work part is to be clamped, the following clamping
devices can be distinguished:
› Mechanical clamping devices
› Hydraulic clamping devices
› Pneumatic clamping devices
› Electric clamping devices
Universal machine vises can be horizontally as well as
vertically turned. Furthermore, there are also vises
that pneumatically generate clamping power.
Figure 2.21 : Precision Sine Vise
Work parts made of iron can be clamped with
electromagnetic devices. The work part is drawn to
the clamping plate after a current is switched on. It
can be easily removed after the current is switched
Figure 1.22 : Electromagnetic Clamping Plate
Milling is a cutting operation with a rotating tool,
whereby the cutting edges are not in operation
all the time. The cutting movement is caused by
the rotation of the tool. Feed direction and
cutting direction do not depend on each other.
It is realized either by the tool or by the work part
or by both of them (Figure 2.23).
The Cutting Speed (Vc) and the Feed Speed (Vf) is
overlap to each other and results in a continuous
The cutting movement is the movement between the tool
and the work part, generating only one nonrecurrent chip
cut during one rotation without a feed movement. Cutting
speed corresponds to circumferential speed of the milling
tool on the current cutting edge. It is expressed as Vc and
m/min. Under consideration of the number of rotations of
the spindle n the following formula is received
Vc = π * d * n in m/min
The cutting speed of a cutting tool depends on the
number of the rotations. The direction constantly changes
however during cutting operation.
The feed movement together with the
cutting movement enables a constant
chip removal during several rotations. In
milling, the feed can be indicated in three
› Feed speed (Vf) in mm / min
› Feed per tooth (fz) in mm
› Feed per milling rotation (f ) in mm
Also known as wire-cut EDM and wire cutting.
A thin single-strand metal wire (usually brass) is fed through the workpiece
submerged in a tank of dielectric fluid (typically deionized water).
Used to cut plates as thick as 300 mm and to make punches, tools, and dies from
hard metals that are difficult to machine with other methods.
Uses water as its dielectric fluid; its resistivity and other electrical properties are
controlled with filters and de-ionizer units.
The water flushes the cut debris away from the cutting zone.
Flushing is an important factor in determining the maximum feed rate for a given
Commonly used when low residual stresses are desired, because it does not require
high cutting forces for material removal.
• Computerized Numerical Control (CNC) -
• Power Supply -The Muscle
• Mechanical Section - The Body
• Dielectric System -The Nourishment
-four major components
• Better stability and higher productivity .
• Higher machining rate with desired
accuracy and minimum surface damage.
• Uses in the production of forming tools.
• To produce plastics moldings, die castings,
forging dies etc.
• Can be applied to all electrically
conducting metals and alloys irrespective of
their melting points, hardness, toughness, or
Special form of EDM - uses a continuously moving
conductive wire electrode.
Material removal occurs as a result of spark erosion as the
wire electrode is fed, from a fresh wire spool, through the
Horizontal movement of the worktable (CNC) determines
the path of the cut.
Application - Machining of super hard materials like
polycrystalline diamond (PCD) and cubic boron nitride
(CBN) blanks, and other composites.
Carbon fiber composites are widely used in aerospace,
nuclear, automobile, and chemical industries, but their
conventional machining is difficult