INDUSTRIAL ORIENTED MINI PROJECT REPORT

ON

COMPUTER NUMERICAL CONTROL(CNC) MACHINE

Submitted in the partial fulfillment

For the award of the

DEGREE OF BACHELOR OF TECHNOLOGY

IN DEPARTMENT OF MECHANICAL ENGINEERING

Academic Session 2016-2020

SUBMITTED BY

R.VAMSHIDHAR REDDY

16RA1A0313

B.TECH

Department of Mechanical Engineering

Kommuri Pratap Reddy Institute of Technology

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 PREFACE

 Training is an integral part of B.Tech and each and every student

has to undergo the training for 4-6 weeks in a company.

This record is concerned about our practical training during the summer vacations after
3rd year. We have taken our practical training in “RAJESHWARA RINGS
Pvt.Ltd(RRPL)” .During this training, we got to learn many new things about the CNC
machine. This training provide to be a milestone in our knowledge of present industry.
Every say and every moment was an experience in itself, an experience which
theoretical study can’t provide.

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 ACKNOWLEDGEMENT

It is my pleasure to be indebted to various people, who directly or indirectly

contributed in the development of this work and who influenced my thinking, behavior
and acts during the course ofstudy.

I expressmy sincere gratitude to Mr.PVINAY KUMAR ( Head Of Department)&

Faculty of Mechanical Department for providing me an opportunity to undergo
summer training at “RAJESHWARA RINGS Pvt.Ltd”(RRPL).

And I also express my sincere gratitude to “Mr.K SIVA RAMA

KRISHNA”(Production Manager) for providing me a platform like RRPLtoincrease
my technical knowledge as well as gaining practical knowledge in CNCMachine, which
helps me to achieve a better job opportunity in my field.

Lastly, I would like to thank the almighty and my parents for their moral support and
my friends with whom I shared my day-to-day experience and received lots of
suggestions that my quality of work.

R.VAMSHIDHAR REDDY
16RA1A0313
B.Tech (Mech)

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CERTIFICATE

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 ABSTRACT
 Computer numerical control (CNC) machines are widely used to manufacture different
parts in different types of materials. It is a highly precise way for manufactures to make
sure all their parts are within the set of tolerances. CNC is a computer controlled
whereas in the past it was manually controlled by the operator.

In the manufacturing filed, and particularly in the area of metal working, Numerical
Control technology has caused something of revolution. Even in the every days before
computers became standard fixtures in every company and in many homes, the
machine tools equipped with Numerical Control system found their special place in the
machine shops. The recent evolution of micro electronics and the never ceasing
computer development , including its impact on Numerical Control , has brought
significant changes to the manufacturing sector in general and metalworking industry in
particular.

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 TABLE OF CONTENTS
S.NO DESCRIPTION Page. No
1. COMPUTER NUMERICAL CONTROL (CNC)…………………………...…………………..……7
1.1 CNC HISTORY…………………………………………………………………….......... 7
1.2 CLASSIFICATION OF CNC MACHINE……………………………................... 7

1.3 CONSTRUCTION DETAILS OF CNC……………………………………………. 8

1.4 CNC COORDINATE SYSTEM…………………………….………………………… 11

2. POSITIONING OF MACHINE ORIGIN…………………………………………………..… 12

3. NUMERICAL CONTROL …………………………………………………………………….… 13

3.1 CNC MOTION CONTROL SYSTEM………………………………………………. 14

4. PART PROGRAMMING……………………………………………………………………….… 15
5. TYPES OF CNC PROGRAMING………………………………………………………………. 17

5.1 CNC PROGRAMING ELEMENT………………………………………….………… 18

5.2 OPERATING MODE………………………………………………………………….… 23

5.3 CNC M/C PARTS AND THEIR FUNCTIONS………………………………….. 24

5.4 G-CODES AND THEIR GROUP……………………………………........................ .25

5.5 METHOD OF INSERTING NEW PROGRAM…………………………………... 27

6. CNC MACHINE START PROCEDURE……………………………………………………... 8

7. OPERATING PANEL KEY OF CNC MACHINE…………………………………………. 29

8. CNC OPERATING…………………………………………………………………………………. 30

8.1 OPERATING PANEL KEYS……………………………………………………….… 30

8.2 OPERATING MODE…………………………………………………………………... 31

9. CNC SETTING&METHOD OF MAKING GEOMETRIC OFFSET……………….… 33

10. SAMPLE PROGRAMS………………………………………………………………………….. 35

11. PROJECT WORK ON CNC……………………………………………………………………….. 40

12. RESULT AND CONCLUSION…………………………………………………………………... 43

13. REFERENCES……………………………………………………………………………………….. 44

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 LIST OF FIGURES
S.NO DESCRIPTION Page. No
1. OPEN LOOP CONTROL SYSTEM…………….…………………………………………... 9

2. CLOSED LOOP CONTROL SYSTEM ………………………………………….………… 10

3. CNC COORDINATE SYSTEM

3.1 FOR MILLING………………….………….............................................................. 11

3.2 FOR TURNING……………………………………………………………………….… 11

3.3 ABSOLUTE COORDINATES……………………………………………………… 12

3.4 INCREMENTAL COORDINATES……………………………………………….. 12

4. NC COORDINATE SYSTEN……………………………………………………………..…… 13

5. CNC MOTION CONTROL SYSTEM

5.1 POINT TO POINT………………..………….………………….…………………… 14

5.2 STRAIGHT CUT….…………………………………………………………………… 14

5.3 CONTOURING ………………………………………………………………….…….. 15

6. TURNING OPERATION……………………………………………………………………… 35

7. TAPER TURNING OPERATIO…….……………………………………………………….. 36

8. PATTERN REPEATING……………………………………………………………………….. 37

9. THREADING OPERATION…………………………………………………........................ 39

LIST OF TABLES
S.NO DESCRIPTION Page. No
1. CNC MACHINE PARTS AND THEIRFUNCTIONS…………………………………… 24

2. SOME G- CODES AND THEIR GROUP…………………………………………………….. 25

3. CNC OPERATING PANEL KEYS…………………..………………………………..……. . 30

4. CNC M/C PARTS AND THEIR FUNCTION……………………………........................ 32

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 1. COMPUTER NUMERICAL CONTROL (CNC)
Computer numerical control (CNC) is the automated control of machining tools (drills,
boring tools, lathes) and 3D printers by means of a computer. A CNC machine processes a
piece of material (metal, plastic, wood, ceramic or composite) to meet specifications by
following a coded programmed instruction and without a manual operator.

1.1 CNC HISTORY

The first CNC machines were built in the year 1940s and 1950s, based on existing tools that
were modified with motors that moved the controls to follow points fed into the system on
punched tape. These early servomechanism were rapidly augmented with analog and digital
computers, creating the modern CNC machine tools that have revolutionized machining
processes.

1.2 CLASSIFICATION OF CNC MACHINE

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 1.3.CONSTRUCTION DETAILS OF CNC
In general, a cnc machine tool consists of the following units:

(i) Computers
(ii) Control systems
(iii) Drive motors
(iv) Tool changes

According to the construction of cnc machine tools, it works in the following manner:-

1. The cnc machine controlled by the computer reads the program and translates it into
machine language, which is a programming language of binary notation used on
computers, not on cnc machines.
2. When the operator starts the execution cycle, the computer translates the binary
codes into electronic pulses which are automatically sent to the machine’s power
units. The control unit compares the number of pulses sent and received.
3. When the motor receives each pulse, they automatically transforms the pulse into
rotations that drive the spindle and lead screw, causing the spindle to rotate and
slide or move the table. The part on the, milling machine table or the tool in the
lathe turret is driven to a position specified by the program.

COMPUTERS:-
Cnc machines introduced in the late 1970s were less dependent on hardware and more
dependent on software. These machines store a program into memory when it is first read
in. This facilitated faster operation when producing number of identical parts, since the
program can be recalled from memory repeated without having to read it again.Cnc
machines use an on-board computer that allows the operator to read, analyze and edit
programmed instruction, while nc machines require operators to make a new tape to alter
a program. In essence, the computers distinguishes cnc from nc as with all computers,the
cnc machines computer also works on binary principal using only two characters, 1 & 0 for
information processing. When creating the program, the programmer does not care about
the machine language,instead he or she simply uses a list of codes i.e., G & M codes and
keys in meaningful information. Special built-in software complies theprogram into machine
language and machine moves the tools by servomotors. However, the ability to program the
machine is dependent on whether there is a computer in the machine control. Modern cnc
machines use 32-bit processors in their computers to allow fast and accurate processing of
information. This result in considerable saving of machining time.

CONTROL SYSTEM:-
There are two types of control systems on nc/cnc machines. The overall accuracy of the
machine is determined by the type of control loop used.

Open loop:The open loop control does not provide positioning feedback to the control
unit. The movement pulses are sent out by the control unit and are received by a special
type of servomotor called a stepper motor. The stepper motor then proceeds with the next

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movement command. Since this control only counts pulse and cannot identify discrepancies
in positioning, the control has no way of knowing whether the tool has reached the proper
location or not. The machine will continue this inaccuracy until somebody finds the error.
The open loop control can be used in applications in which there is no change in load
conditions, such as the cnc drilling machine. The advantage of open loop control system is
that it is less expensive, since I does not require the additional hardware and electronics
needed for positioning feedback. The disadvantage is difficulty of detecting positioning
error.

Closed loop:In the closed loop control system, the electronic movement pulses are sent
from the control to the servomotor, enabling the motor to rotate with each pulse. The
pulses are detected and counted by a feedback device called a transducer. With each step of
movement, a transducer sends a signal back to the control, which compares the current
position of the driven axis with the programmed position. When the number of pulses and
received match, the control starts sending out pulses for the next movement. Closed loop
systems are very accurate. Most have an automatic compensation for error, since the
feedback device indicates the error and the control makes the necessary adjustment to
bring the slide back to its position. They use ac,dc or hydraulic servomotors.

Drive Motors:The drive motors control the machine slide movement on cnc equipment.
They are classified into four basic types as follows:-

1.Stepper motor:These convert a digital pulse generated by the microcomputer unit

(mcu i.e. machine control unit) into small step rotation. Stepper motors have a certain
number of steps that can travel. The number of pulses that the mcu sends to the stepper

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motor controls the amount of rotation of the motor. Stepper motors are mostly used in
applications where low torque is required. Stepper motors are used in open loop control
system, while ac, dc or hydraulic servomotors are used in closed loop control system.

2. Dc servomotors: These are variable speed motors that rotate in response to the
applied voltage. They are used to drive a lead screw and gear mechanism. Dc servos provide
high torque output than stepper motors.

3. Ac servomotors:These are controlled by varying the voltage frequency to control

speed. They can develop more power than a dc servo. They are also used to drive a lead
screw and gear mechanism.

4.Fluid servomotors: It is also a variable speed motor. They are able to produce more
power or more speed in the case of pneumatic motors than electric servomotors. They
hydraulic pump provides energy to valves which are controlled by the mcu.

Tool changers:Most of the time, different cutting tools are used to produce one part of
machine. The tools have to be replaced quickly for the next machining operation. Owing to
this reason, the majority of cnc machine are equipped with automatic tool changer, such as
magazines on machining centers and turrets on turning centre. Tool changers may be
equipped for either random or sequential tool selection. In random tool selection, there is
no specific pattern of tool selection on machining centre, when the program calls for the
tool; it is automatically indexed into waiting position, where it can be retrieved by the tool
handling device. On the turning centre, turret automatically rotates, bringing tools into
position.

1.4 CNC COORDINATE SYSTEM

FOR MILLING:
In order for the part programmer to plan the
Sequence of positions and movements of the
cutting tool relative to the work piece,
it is necessary to establish a standard axis system by
which the relative positions can be specified.
However, to make things easier for the programmer,
we adopt the view point that the work piece is
stationary while the drill bit is moved related to the
table. Accordingly, the coordinate system of axes is
established with respect to the machine table. Two
axes X and Y, are defined in the plane of the table, as
shown in figure. The Z axes is perpendicular to this
plane and movement in the Z direction is controlled
by vertical motion of the spindle. The positive and
negative directions of motion of tool relative to table along these axes are as shown in the
figure.Cnc drill presses are classified as either two axes or three axes machines, depending
on whether or not they have the capability to control the Z axes.

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FOR TURNING:-For turning operation, two axes are normally at that are required to
command the movement of the tool relative to the rotating work piece. The Z axis is the axis
of rotation of the work part and X axis defines the radial location of the cutting tool. This
arrangement is illustrated in the fig. the purpose of the coordinate system is to provide a
means of locating the tool in relation to the work piece. Depending on the cnc machine, the
part programmermay have several different
options available for specifying this location.

2. POSITIONING OF MACHINE ORIGIN

Fixed zero: The programmer must determine the position of the tool relative to the
origin (zero point) of the coordinate system. Cnc either of two methods for specifying
the zero point. The first possibility is for the machine to have a fixed zero. In this case,
the origin is always located at the some position the machine table. Usually, that
position is the southwest corner(lower left-hand cornr) of the table and all tool
locations will be defined by positive X and Y coordinates.

Floating zero: The second and more common feature on modern cnc machines
allows the machine operator to set the zero point any position on the machine table.
This feature is called floating zero. The part program is the one who decides where the
zero point should be located. The decision is based on part programming convince.

MODE OF POSITIONING:

Absolute Coordinates:Another option sometimes available to the part programmeris

to use either an absolute system of tool positioning or an incremental system. Absolute
positioning means that the tool locations are always defined in relation to the zero point. If
a hole is to be drilled at a spot that is 8 in. Above the X axis 6 in. To the right of the Y axis,
the coordinate location of the hole would be specified as X=+6.000 and Y=+8.000

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Incremental positioning:
Incremental positioning means that the next tool location must be defined with difference
to the previous too location. If in our drilling example, suppose that the previous hole had
been drilled at an absolute position of X=+4.000 and Y=+5.000. Accordingly , the incremental
position instructions would be specified as X=+2.000 and Y=+3.000, in order to move the
drill to the desired spot.

3.NUMERICAL CONTROL(NC)
Programmable automation in which the mechanical actions of a ‘Machine Tool’ are
controlled by a program containing coded alphanumeric data that represents relative
positions between a work head and a work part.

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NC COORDINATE SYSTEMS:
For flat and prismatic (block like) parts:

 Milling and drilling operations

 Conventional Cartesian coordinate
system
 Rotational axes about each linear axis
For rotational parts:
 Turning operations
 Only X and Z axes

CNC MOTION CONTROL SYSTEMS

In order to accomplish the machining process, the cutting tool and work piece must to be
movies relative to each other. In cnc, there are three basic types of motion control system.

1.Point-to-point cnc(PTP): It is also sometimes

called a positioning system. In ptp, the objective of
the machine tool control system is to move the
cutting tool to a predefined location. The speed or
path by which this movement is accomplished is
not important in ptp cnc. Once the tool reaches
the desired location, the machining operation is
performed at that position.

2.Straight-cut cnc: Straight-cut control system

are capable of moving the cutting tool parallel to one of the
major axes at a controlled rate suitable for machining. It is
therefore appropriate performing milling operation to
fabricated work pieces of rectangular configuration. With this
type of cnc system it is not possible to combine movements in
more than a single axis direction. Therefore, angular cuts on
the work piece would not be possible. A cnc machine capable
of straight cut movements is also capable of ptp movements.

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3.Contouring cnc: Contouring is the most
complex, the most flexible, and the most
expensive type of machine tool control. It is
capable of performing both ptp and straight-
cut operation. In addition, the distinguishing
feature of contouring cnc systems is their
capacity for simultaneous control of more
than one axis movement of the machine tool.
The path of the cutter is continuously
controlled to generate the desired geometry
of the work piece. For this reason, contouring
system is also called continuous-path cnc system.

4.Linear Interpolation:
Linear Interpolation consists of any programmed points linked together by straight lines,
whether the points are close together or far apart (Fig. 11). Curves can be produced with
linear interpolation by breaking them into short, straight-line segments. This method has
limitations, because a very large number of
points would have to be programmed to describe
the curve in order to produce a contour shape. A
contour programmed in linear interpolation
requires the coordinate positions (XY positions in
two-axis work) for the start and finish of each
line segment. Therefore, the end point of one
line or segment becomes the start point for the
next segment, and so on, throughout the entire
program.

5.Circular Interpolation:
The development of MCUs capable of circular
interpolation has greatly simplified the process
of programming arcs and circles. To program
an arc (Fig. 12), the MCU requires only the
coordinate positions (the XY axes) of the circle
center, the radius of the circle, the start point
and end point of the arc being cut, and the
direction in which the arc is to be cut
(clockwise or counterclockwise) See Fig. 12.
The information required may vary with
different MCUs.

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 4.PART PROGRAMMING

The programmer carefully converts the sequence of operations to set off instruction,
i.e.,(part program). Part programming consists of sequence of blocks, each block has a
specific function to perform. Machine read one block & command the tool or other slides to
perform that operation. After this controller shifts to the next block. In this way complete
machining is performed which consists of small step operation define by each block
.example,
Format : G02 x_z_i_k_f_(i,k format)
Or G02 x_z_r_f_
Here ,in first syntax,
i= distance between start point& centre point of arc along x-axis.
K=distance between start point& centre point of arc along z-axis.
In second syntax,
r= radius of the arc.
The G02 command is utilized to move the tool in the
circular arc profile with G02 the movement will be in the clockwise direction. The
movement taken will be at the programmed feed rate.

Manual part program:-The program contains G and M codes. G codes are called predatory
codes. They prepare the machine for cutting operation e.g. linear interpolation, circular
interpolation, rapid etc. M codes are called miscellaneous codes they perform all other
operation except for cutting like spindle on/off,
N10 G90 G00 X+100 Y-100 Z+50;(single block)

Block of Information:CNC information is generally programmed in blocks of five words. Each

word conforms to the EIA standards and they are written on a horizontal line. If five
complete words are not included in each block, the machine control unit (MCU) will not
recognize the information, therefore the control unit will not be activated. Using the
example shown in Fig. 17 , the five words are as follows: N001 represents the sequence
number of the operation. G01 represents linear interpolation X12345 will move the table
1.2345 in. in a positive direction along the X axis. Y06789 will move the table 0.6789 in.
along the Y axis. M03 Spindle on CW.

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Programming tips:
Programming is just like any other work with good knowledge and appositive attitude; it can
be done right and with first class results. Here are some tips to get the best results from any
programming effort.
1. Approach cnc programming in a logical and methodological way.
2. Always calculate unknown values never guess.
3. Standardized a programming style and adhere to it.
4. Program dimensional values in absolute mode whenever possible.
5. Make a setup sheet and/or tooling sheet before programming, not after.
6. Program has many machining operations in a single setup as possible.
7. Use minimum number of tools for maximum number of jobs standardize.
8. Always program for the safety for cnc machining.
9. Document your work and store everything relating to the program development.
10. Watch for programming errors-syntax and logical-all errors are avoidable.

Advantages of CNC machine:

Most of the advantages derived from cnc technology are due to the high level of
automation, high flexibility of cnc machines and their ability to combine multifunction
machining requirements in minimum number of workstations and setups. The significant
advantages are as follows:
 High accuracy and repeatability.
 Reduced inspection.
 Ease of assembly and interchangeability.
 Less scrap and rework.
 Reduction in floor space/ number of persons/handling, results in better management
control over the production.
 Development of new work is done faster with the usage of cnc machines.
 Saving in jigs and fixtures as well as in dead time.
 Less material handling.
 Cost accounting and production control becomes very precise.
 Dependence on skilled operators can be dispensed with.
 Optimum utilization of horse power of the machine.
 Increase effective machine utilization.
 Less paper work.

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 5. TYPES OF CNC PROGRAMING
CNC programming is made of blocks & blocks are made by commands. Commands are
provided for different functions.

5.1 CNC PROGRAMING ELEMET

Command: Command is the combination of alphabetic character & numerical

value where alphabetic is used for address & numerical is used for
value. Alphabet A - Z, numerical 0-9. Ex.G0 X4 Z2 N1

Block: Group of commands known as block. One block has one or more
commands. Block is started from sequence number and endedby end of block
command where sequence number is optional.

Different addressing codes:-

G-codes: These are preparatory function codes and used for different
functions.

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1.Axis movement:G0, G01, G02, G03, codes are used for programming of any axis.
 G00= This code is used for tool positioning & free movement in air.
Format--G00 X…Z…;
 G01= This code is used for linear movement of axis.
Format--G01 X… Z… F…;
 G02= This code is used for linear movement of axis.
Format—G02 X… Z… R… F…;
 G03= This code is used for linear movement of axis.
Format—G02 X… Z… R… F…;
 G28= This code is used for linear movement of axis.
Format—G28 U0.0 W0.0;
2.Dwell Time:
 G04X….(time in second)
 G04 U….(time in second)
 G04 P….(time in m.s.)
3.Plane Selection:
 G17X-Y plane selection
 G18X-Z plane selection
 G19Y-Z plane selection
4.Inch/mm Mode Setting:
 G20-program in inch
 G21-program in mm
5.Stroke Check Function
 G22-Stored stroke check function On
 G23-Stored stroke check function Off

6.Referanc return:
 G27- reference return check
 G28- 1st ref. point
 G29- return from 0 point
 G30- 2nd ref. point

7.Skip Function:
 G31- skip function

8.Thread Cutting:
 G32- thread cutting
 G34- variable lead threading cutting

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9. Tool Nose Radius:
 G40- Tool nose radius compensation cancel
 G41- Tool nose radius compensation left
 G42- Tool nose radius compensation right

10.Coordinate System (50 series):

 G50- coordinate system setting or max. spindle rpm.
 G52-local coordinate system setting
 G53-machine coordinate system setting
 G54-work piece coordinate system 1 selection
 G55-work piece coordinate system 2 selection
 G56-work piece coordinate system 3 selection
 G57-work piece coordinate system 4 selection
 G58-work piece coordinate system 5 selection
 G59-work piece coordinate system 6 selection

11. Canned Cycle (G70 & G80 series):

 G70- finishing cycle of G71, G72, G73
 G71- stock removal of turning
 G72- stock removal of facing
 G73- pattern repeating
 G74- end face peck drilling
 G75- outer/internal diameter drilling
 G76- multiple thread cycle
 G77- pocket cutting and turning
 G78- single threading cycle
 G79- pocket cutting and facing
 G80- canned cycle cancel

12 Mode setting (G90 series):

 G90- Absolute programming
 G91- incremental programming
 G92- max. spindle rpm
 G94- feed mm per min.
 G95- feed mm per revolution
 G96- constant surface speed control
 G97- cancellation of G96
 G98- return to initial point
 G99- return to r point

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M-CODES:Theseare miscellaneous function codes and it is used for start /stop of any
function.
 M00- Program stop
 M01- Optional stop
 M02- Program end and restart
 M03- Spindle rotation CW
 M04- Spindle rotation CCW
 M05- Spindle stop
 M06- Tool changing in VMC
 M07- Coolant On
 M08- Coolant On/Off
 M09- Coolant Off
 M10- Chuck Declamp
 M11- Chuck Clamp

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 M16- Chuck ID selection
 M18- Chuck OD selection
 M19- Spindle Orientation
 M20- Spindle Orientation cancel
 M30- End of Main program
 M32- Tailstock Quill forward
 M33- Tailstock Quill retract
 M34- Parts catcher forward
 M35- Parts catcher retract
 M46- Door open
 M47- Door close
 M50- Spindle lock
 M51- Spindle unlock
 M78- Steady rest open
 M79- Steady rest hold
 M82- Tail stock body fwd./unclamp
 M83- Tail stock body ret./clamp
 M84- Touch probe arm forward
 M85- Touch probe arm retract
 M98- Sub program call
 M99- Sub program end

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 Different addressing codes in CNC:
 A-Extra axis
 B-Extra axis
 C-Extra axis
 D-Cutter dia in VMC
 F-Feed on axis
 G-G code program
 H-Tool length offset in VMC
 I-The value of X from start point of radius to center of radius.
 J-The value of Y from start point of radius to center of radius
 K-The value of Z from start point of radius to center of radius
 L-Loop in VMC
 M-M code group
 N-Sequence number
 O-Program number
 P-Peak depth in X
 Q-Peak depth in Z
 R-Radius
 S-Spindle
 T-Tool no. and offset no. in CNC
 U-X axis value in incremental program
 V-Y axis value in incremental program
 W-Z axis value in incremental program
 X- X axis value in absolute program
 Y- Y axis value in absolute program
 Z- Z axis value in absolute program

PROGRAM SCAN: CNC m/c Scan the program sequentially in blocks from Top
block to Bottom block.
PROGRAM HEADER:
 Program No.
 Sequence No.
 Cancellation command
 M/c home position
 Tool & offset selection
 Spindle rpm with direction
 Coolant On
 Tool positioning

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PROGRAM FOOTER:
 Tool return to home position
 Spindle stop
 Coolant off
 Program End & Reset

5.2.OPERATING MODE

1.Manual mode: Manual mode is used for individual start/stop function.

Different functions:

Chuck clamp/D-clamp –Chuck is used for holding the job.

Method—
Step 1-Select jog mode
Step 2- Chuck clamp/ decamp by foot switch

Conditions—All axis should be at home

Turret index—Turret is the tool holding device used for holding the tool & supporting
against cutting force.
Different stations are used for holding different tools 8 station turret is using in this
machine.
Conditions—All axis should be at home.

2.Auto mode: Auto is used for automatic running of NC program

Single block—Block by block running program.

Method—
Step 1—select auto
Step 2—select single block
Step 3—Press cycle start button -> single block
Will work on pressing one time to the cycle start button for next repeating cycle start
button.

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5.3.CNC MACHINE PARTS AND THEIR FUNCTIONS

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5.4 SOME G- CODES AND THEIR GROUP

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`28
5.5.METHOD OF INSERTING NEW PROGRAM

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6.CNC MACHINE START PROCEDURE

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7.OPERATING PANEL KEY OF CNC MACHINE

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 8. CNC OPERATING

8.1 Operating panel keys:

`

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8.2 Operating mode:

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`34
 9. CNC SETTING

OFFSET: To make a new point in software or shafting any point in software from its
actual position is known as offset.

WORKSHIFT OFFSET: Work shift Offset

is used for shifting the job origin from actual
position by giving the value in software.

GEOMETRY OFFSET:Geometry offset is used

for making job origin or job centre at a distance
from machine home position. Geometry Offset
is used for tool held in the turret each tool
requires separate geometry offset.
.

WEAR OFFSET: Wear offsets is to make

slight adjustment of tool and bring the part
within the correct tolerance.

METHOD OF MAKING GEOMETRIC OFFSET

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10. SAMPLE PROGRAMS

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1.TURNING OPERATION:

2.TAPERING OPERATION:

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3.PATTERN REPEATING:
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4.THREADING:

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`40
`41
 11.PROJECT WORK ON CNC MACHINE
TURNING OPERATION:

PROGRAM:
 1ST OPERATION

O2255;

N1;

G28 U0.0 W0.0;

G97 S2000 M03;
T0101 M07;
G0 X50.0 Z20.0
Z2.5;
G01 X29.0 F0.15;
G0 X50.0 Z3.5;
G0 Z1.8;
G01 X29.0 F0.15;
G0 X50.0 Z2.5;
Z1.1;
G01 X29.0 F0.15;
G0 X50.0 Z1.5;
Z0.7;
G01 X29.0 F0.15;
G0X46.0 Z2.0;
G01 Z-10.0 F0.15;
G0 X47.0 Z2.0;
X44.0;
G01 Z-1.98 F0.15;
G0 X46.0 Z0.0;
G01 X27.0 F0.15;
G0 X39.0 Z0.5;
G01 G42 X41.62 Z0.0 F0.15;
G01 X43.44 A110.0 F0.08;

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G03 X43.70 Z-0.52 R0.2 F0.08; G0 X35.0 Z10.0;
G01 G40 Z-2.0 F0.15; G0 Z2.0;
G01 X43.8; X35.6;
G03 X45.45 Z-2.9 R0.9; Z1.0;
G01 Z-9.0 F0.12; G01 G41 X33.6 Z0.0 F0.1;
G0 U2.0; A250.0 R0.5 F0.1;
G0 Z20.0; A200.0 X31.8 Z-0.95 F0.1;
G28 U0.0 W0.0 M05; G01 G40 U-1.0;
M01; Z20.0 M09;
N2; G28 U0.0 W0.0 M05;
G28 U0.0 W0.0 ; M01;
G97 S2000 M03; M30;
T0303 M07;
G0 X27.0 Z10.0;  2nd OPERATION:
Z2.0;
/ G01 Z-25.5 F0.15; O0995;
/G0 U-1.0 Z1.0; N1;
/X29.5; G28 U0.0 W0.0;
/G01 Z-25.5 F0.15; G97 S2000 M03;
/G0 U-1.0 Z1.0; T0707 M07;
X30.0 G0 X50.0 Z20.0;
G01 Z-25.5 F0.15; Z2.0;
G0 U-1.0 Z1.0; /G01 X29.0 F0.15;
X31.2; /G0 X50.0 Z3.0;
G01 Z-25.5 F0.15; /Z1.5;
G0 U-1.0 Z1.0; /G01 X29.0 F.15;
Z20.0 M09; /G0 X50.0 Z1.5;
G28 U0.0 W0.0 M05; /Z0.5;
M01; /G01 X29.0 F0.15;
N3; /G0 X46.0 Z2.0;
G28 U0.0 W0.0; /G01 Z-15.0 F0.15;
G97 S2000 M03; /G0 X47.0 Z2.0;
T0404 M07; X44.0;

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G01 Z-1.98 F0.15; G0 X51.0 Z10.0;
G0 X46.0 Z0.0; G0 Z1.0 M07;
G01 X27.0 F0.15; G01 Z-5.5 F0.25;
G0 X39.0 Z0.5; G01 X50.45 F0.15;
G01 G42 X41.62 Z0.0 F0.15; G02 X50.45 Z-16.0 R7.74;
G01 X43.44 A110.0 F0.08; G0 U2.0;
G03 X43.70 Z-0.52 R0.2 F0.08; G0 Z-5.5;
G01 G40 Z-2.0 F0.15; G01 X49.45 F0.15;
G01 X43.8; G02 X49.45 Z-16.0 R7.74;
G03 X45.45 Z-2.9 R0.9; G0 U2.0;
G01 Z-18.0 F0.12; G0 Z-5.5;
G0 U2.0; G01 X48.45;
G0 Z20.0; G02 X48.45 Z-16.0 R7.74;
G28 U0.0 W0.0 M05; G0 U2.0;
M01; G0 Z-5.5;
N2; G01 X47.45;
G28 U0.0 W0.0; G02 X47.45 Z-16.0 R7.74;
G97 S2000 M03; G0 U2.0;
T0202 M07; Z-5.5;
G0 X35.0 Z20.0; G01 X46.45;
G0 Z1.0; G02 X46.45 Z-16.0 R7.74;
G01 G41 X35.40 Z0.0 F0.18; G0 U2.0;
G01 X35.22 A240.0 F0.08; G0 Z-4.0;
G02 X32.58 Z-1.62 R3.0; G01 G42 X45.55 Z-5.13 F0.12;
G01 X31.70 A200.0; G03 X44.59 Z-6.18 R1.5
G0 G40 U-1.0; G02 X44.59 Z-17.02 R7.74;
G0 Z20.0 M09; G03 X45.65 Z-18.07 R1.5;
G28 U0.0 W0.0 M05; G0 G40 U2.0;
301; G0 Z20.0 M09;
N3; G28 U0.0 W0.0 M05;
G28 U0.0 W0.0; M01;
G97 S2000 M03; M10;
T0101; M30;

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 12.RESULT & CONCLUSION

 Hence I have successfully studied about the CNC machine tools and their functions. With
their G & M codes and operation performed on
these type of machine tool.

 The importance of lathes and milling machines even if they are conventional cannot be
undetermined. These machines have played a real important role in bringing about
industrial revolution and have laid the foundations. But the bringing about of the new
technology in the present era is very important. The conventional machines required in a
small quantities whereas the CNC machines must be increased to improve the quantity and
quality of production.

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 13.REFERENCES

1.www.wikipedia.org/wiki/Main

2. CNC Programming Basics text by Steve Krar & Arthur Gill

@www.engr.uvic.ca

3. www.slideshare.net

4. http://www.yourpersonal plc tutor site.htm

5.http://www.pc-control.co.uk/index.hmt

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