CONTENTS PAGES

INTRODUCTION

SAFETY

MACHINE

PROCEDURE

PROJECT PICTURE

CONCLUSION

DISCUSSION

INTRODUCTION

What are CNC?

CNC stands for Computer Numerical Control and it has been around since the

early 1970’s. Before it was christened CNC, it was called NC, for Numerical Control. When

computers were introduced during 1070’s, the name changed. It has stroked almost all

manufacturing forms in almost all stages of production. CNC machines either substitute

some existing manufacturing processes or combine work with them.

A CNC program is just any other set of instructions. It’s written like a sentence and

the order of operation is chronological. The machine will then execute that set of instructions

step-by-step. A special series of CNC words/codes are used to relay what the machine is

supposed to do. CNC codes begin with letter addresses (like S for spindle speed, and X, Y &

Z for common linear axis motions).

When certain codes are arranged together in a coherent method, this group of CNC

codes create a “command” that is like a sentence. A common CNC machine will only be

needing around 40-50 words/codes to program different commands

THE CAM

CAM stands for Computer Aided Manufacturing. It simplifies the programming

processes which are new, and added to the CNC program regularly. Of course, the easy

applications can be programmed with only the simplest machines around: the pen, paper

and calculator. However, more complex programs are vital regularly. It is when composing

these programs become much more tricky and (worse) tedious.

The CAM is a program that runs on a computer that aids the CNC programmer with

the programming. It also works hand-in-hand with the CAD (Computer Aided Design) design

drawing (those designs engineers compose/nurture). With the CAM helping, redefinition of

the work-piece configuration is not needed. What the CNC programmer is left to do is just to

specify the machine operations to be executed and the CAM system will compose the CNC

program automatically.

THE DNC SYSTEM

DNC stands for Distributive Numerical Control. It is a computer that is connected with

one or more CNC machines, forming a network. When a program is manually composed and

ready to be loaded to the CNC control, it is being typed right into the control. However, this is

like using the CNC machine as a luxurious keyboard. Moreover, if the CNC program is

achieved with the help of CAM, it is already in text form and ready to be loaded to the CNC

control. The DNC simply distributes the CNC program to more than one CNC machine.

Fields or industry that are using CNC machine

1. In the metal removal industry

2. In the metal fabrication industry

3. In the electrical discharge machining industry

4. In the woodworking industry

Types of CNC machines

CNC milling machines are traditionally programmed using a set of commands known as G-

codes & M-codes. These types of codes are representing specific CNC functions in

alphanumeric format.

G-codes Description

GOO Rapid positioning

G01 Linear interpolation

G02 Circular interpolation, clockwise

G03 Circular interpolation, counterclockwise

G04 Dwell

G05

P10000

High-precision contour control (HPCC)

G05.1 AI Nano contour control

Q1.

G07 Imaginary axis designation

G09 Exact stop check

G10 Programmable data input

G11 Data write cancel

G12 Full-circle interpolation, clockwise

G13 Full-circle interpolation, counterclockwise

G17 XY plane selection

G18 ZX plane selection

G19 YZ plane selection

G20 Programming in inches

G21 Programming in millimeters (mm)

G28 Return to home position (machine zero, aka machine reference point)

G30 Return to secondary home position (machine zero, aka machine reference

point)

G31 Skip function (used for probes and tool length measurement systems)

G33 Constant-pitch threading

G34 Variable-pitch threading

G40 Tool radius compensation off

G41 Tool radius compensation left

G42 Tool radius compensation right

G43 Tool height offset compensation negative

G44 Tool height offset compensation positive

G45 Axis offset single increase

G46 Axis offset single decrease

G47 Axis offset double increase

G48 Axis offset double decrease

G49 Tool length offset compensation cancel

G50 Scaling function cancel

G52 Local coordinate system (LCS)

G53 Machine coordinate system

G54 to G59 Work coordinate systems (WCSs)

G54.1 P1 to

P48

Extended work coordinate systems

G73 Peck drilling cycle for milling - high-speed (NO full retraction from pecks)

G74 Tapping cycle for milling, left hand thread, M04 spindle direction

G76 Fine boring cycle for milling

G80 Cancel canned cycle

G81 Simple drilling cycle

G82 Drilling cycle with dwell

G83 Peck drilling cycle (full retraction from pecks)

G84 Tapping cycle, right hand thread, M03 spindle direction

G84.2 Tapping cycle, right hand thread, M03 spindle direction, rigid tool holder

G90 Absolute programming

G91 Incremental programming

G92 Position register (programming of vector from part zero to tool tip)

G94 Feedrate per minute

G97 Constant spindle speed

G98 Return to initial Z level in canned cycle

G99 Return to R level in canned cycle

M-codes Description

M00 Compulsory stop

M01 Optional stop

M02 End of program

M03 Spindle on (clockwise rotation)

M04 Spindle on (counterclockwise rotation)

M05 Spindle stop

M06 Automatic tool change (ATC)

M07 Coolant on (mist)

M08 Coolant on (flood)

M09 Coolant off

M10 Pallet clamp on

M11 Pallet clamp off

M13 Spindle on (clockwise rotation) and coolant on (flood)

M19 Spindle orientation

M21 Mirror, X-axis

M22 Mirror, Y-axis

M23 Mirror OFF

M30 End of program with return to program top

M48 Federate override allowed

M49 Federate override NOT allowed

M60 Automatic pallet change (APC)

M98 Subprogram call

M99 Subprogram end

CNC Milling

Computer Numerical Control (CNC) Milling is the most common form of CNC. A milling

machine is a machine tool used to machine solid materials .Milling machines are often

classed in two basic forms, horizontal and vertical. CNC mills are classified according to the

number of axes that they passes .Axes are labeled as x and y for horizontal movement, and

z for vertical movement .A standard manual light-duty mill (such as a Bridgeport) is

typically assumed to have four axes:

1. Table x.

2. Table y.

3. Table z.

4. Milling Head z.

Other than that, CNC milling can perform the functions of drilling and often turning.

The number of axis of a milling machine is a common subject of casual "shop talk"

and is often interpreted in varying ways. A five-axis CNC milling machine has an extra axis in

the form of a horizontal pivot for the milling head, as shown below. This allows extra

flexibility for machining with the end mill at an angle with respect to the table. A six-axis CNC

milling machine would have another horizontal pivot for the milling head, this time

perpendicular to the fifth axis.

COMPENANT OF MECHINE

Objective

Introduced to CNC (computer numerical control) of its uses.

Can differentiate the programmer code of G-codes and M-codes

Can understand the description of the G-code and M-code

Can prepare programmer code for the project that have been given after been

introduced to its codes.

Know how to key-in the programmer into the computer for see its simulation.

Can operate the CNC machine without any problem.

Always aware with the vital of self, machine and workshop safety

Project

We have been given an project where we need to construct name of one of

the polytechnic in Malaysia in a graph paper with its scales for each symbol. Then,

we have prepare the programmer code for the name .We have been told that, the

project must be try its simulation before key-in into the CNC milling machine so that

the works done will more accurate or perfect .These project can be done using CNC

milling through an drilling process.

SAFETY

Self - Safety

1. Wear safety glasses and side shields at all times.

2. Do not wear rings or jewelry that could get caught in a machine.

3. Keep long hair covered or tied back while operating machine.

4. Keep hands away from moving machine parts.

5. Use proper materials to lift heavy materials. A back injury can ruin your

career.

6. Safety shoes with steel toes and oil-resistant soles should be worn to protect

our feet from dropped objects.

7. Watch out for burrs on machined parts.

8. Always obey your lecturer’s directive before doing any work.

Machine Safety

1. Do not operate a machine unless all safety guards in place.

2. Never remove chips from a moving tool.

3. Securely clamp all parts.

4. Stop the spindle completely before doing any setup or piece loading and

unloading.

5. Keep tools off the machine and its moving parts.

6. Use proper speeds and feeds. Reduce feed and speed if you notice unusual

vibration or noise.

7. Dull or damaged tools break easily and unexpectedly.

8. Make sure coolant is in “ON” mode when a project is in progress.

9. Make sure the emergency stop button at the machine is operational.

Workshop Safety

1. Keep area clean.

2. Do not play or run inside the workshop.

3. Keep the used tools in its original place.

4. Sweep up chips and clean up any oil or coolant that people could slip on.

5. Always obey the workshop safety rules and its precaution.

6. Always be aware of self-safety and machine which can cause dangerous to

our self and other people in the workshop.

7. Do not pour any slippery liquids to the ground of the workshop.

8. Make sure the workshop is clean and all the tools are in their original places

before leaving the workshop.

MACHINE

CNC Milling Machine

PROCEDURE

N01 G71 G90 G17 G40

N02 G54

N03 M27

N04 T=”DRILL 10”

N05 M06

N06 M07

N07 S1200 M03

N08 G00 X10 Y88

N09 G01 Z-5 F100

N10 G01 X10 Y90

N11 G01 X20 Y90

N12 G01 X20 Y88

N13 G00 Z10 F100

N14 G00 X15 Y90

N15 G01 Z-5 F100

N16 G01 X15 Y70

N17 G00 Z10 F100

N18 G00 X27 Y90

N19 G01 Z-5 F100

N20 G01 X25 Y90

N21 G01 X25 Y75

N22 G03 X35 Y75 I=AC(30) J=AC(75)

N23 G01 X35 Y90

N24 G01 X33 Y90

N25 G00 Z10 F100

N26 G00 X42 Y70

N27 G01 Z-5 F100

N28 G01 X40 Y70

N29 G01 X40 Y90

N30 G01 X50 Y70

N31 G01 X50 Y90

N32 G01 X40 Y90

N33 G00 Z10 F100

N34 G00 X12 Y60

N35 G01 Z-5 F100

N36 G01 X10 Y60

N37 G01 X10 Y40

N38 G01 X12 Y40

N39 G00 Z10 F100

N40 G00 X10 Y40

N41 G01 Z-5 F100

N42 G01 X20 Y40

N43 G01 X20 Y60

N44 G01 X10 Y60

N45 G00 Z10 F100

N46 G00 X10 Y50

N47 G01 Z-5 F100

N48 G01 X20 Y50

N49 G00 Z10 F100

N50 G00 X27 Y60

N51 G01 X25 Y60

N52 G01 X25 Y45

N53 G03 X35 Y45 I=AC(30) J=AC(45)

N54 G01 X35 Y60

N55 G01 X33 Y60

N56 G00 Z10 F100

N57 G00 X42 Y45

N58 G01 Z-5 F100

N59 G01 X40 Y45

N60 G03 X45 Y50 I=AC(45) J=AC(45)

N61 G02 X50 Y55 I=AC(45) J=AC(55)

N62 G01 X40 Y55

N63 G00 Z10 F100

N64 G00 X57 Y45

N65 G01 Z-5 F100

N66 G01 X55 Y45

N67 G03 X60 Y50 I=AC(60) J=AC(45)

N68 G02 X65 Y55 I=AC(60) J=AC(55)

N69 G01 X63 Y55

N70 G00 Z10 F100

N71 G00 X80 Y50

N72 G01 Z-5 F100

N73 G01 X80 Y60

N74 G01 X75 Y60

N75 G03 X70 Y55 I=AC(75) J=AC(55)

N76 G01 X70 Y45

N77 G03 X75 Y40 I=AC(75) J=AC(45)

N78 G01 X80 Y40

N79 G01 X80 Y42

N80 G00 Z10 F100

N81 G00 X70 Y50

N82 G01 Z-5 F100

N83 G01 X80 Y50

N84 G00 Z10 F100

N85 G00 X85 Y58

N86 G01 Z-5 F100

N87 G01 X85 Y60

N88 G01 X95 Y60

N89 G01 X95 Y50

N90 G00 Z10 F100

N91 G00 X90 Y60

N92 Z-5 F100

N93 G01 X90 Y40

N94 G01 X85 Y40

N95 G01 X85 Y42

N96 G01 X85 Y40

N97 G01 X95 Y40

N98 G01 X95 Y42

N99 G00 Z10 F100

N100 G00 X102 Y40

N101 Z-5 F100

N102 G01 X100 Y40

N103 G01 X100 Y60

N104 G01 X110 Y40

N105 G01 X110 Y60

N106 G01 X108 Y60

N107 G00 Z10 F100

N108 G00 X10 Y30

N109 Z-5 F100

N110 G01 X10 Y10

N111 G01 X15 Y10

N112 G03 X20 Y15 I=AC(15) J=AC(15)

N113 G01 X20 Y25

N114 G03 X15 Y30 I=AC(15) J=AC(25)

N115 G01 X10 Y30

N116 G01 X10 Y10

N117 G00 Z10 F100

N118 G00 X27 Y10

N119 Z-5 F100

N120 G01 X25 Y10

N121 G01 X25 Y25

N122 G02 X35 Y25 I=AC(30) J=AC(25)

N123 G01 X35 Y10

N124 G01 X33 Y10

N125 G00 Z10 F100

N126 G00 X25 Y20

N127 Z-5 F100

N128 G01 X35 Y20

N129 G00 Z10 F100

N130 G00 X40 Y20

N131 Z-5 F100

N132 G01 X40 Y30

N133 G01 X50 Y30

N134 G01 X50 Y20

N135 G00 Z10 F100

N136 G00 X45 Y30

N137 Z-5 F100

N138 G01 X45 Y10

N139 G00 Z10 F100

N140 G00 X55 Y25

N141 Z-5 F100

N142 G01 X65 Y15

N143 G01 X65 Y25

N144 G03 X55 Y25 I=AC(60) J=AC(25)

N145 G01 X55 Y15

N146 G03 X65 Y15 I=AC(60) J=AC(15)

N147 G00 Z10 F100

N148 G00 X80 Y25

N149 Z-5 F100

N150 G01 X90 Y15

N151 G01 X90 Y25

N152 G03 X80 Y25 I=AC(85) J=AC(25)

N153 G01 X80 Y15

N154 G03 X90 Y15 I=AC(85) J=AC(15)

N155 G00 Z10 F100

N156 G00 X97 Y10

N157 Z-5 F100

N158 G01 X95 Y10

N159 G01 X95 Y30

N160 G01 X105 Y10

N161 G01 X105 Y30

N162 G01 X103 Y30

N163 G00 Z10 F100

N164 G00 X112 Y10

N165 Z-5 F100

N166 G01 X110 Y10

N167 G01 X110 Y30

N168 G01 X120 Y10

N169 G01 X120 Y30

N170 G01 X110 Y30

N171 G00 Z10 F100

N172 M27

N173 T0

N174 M06

N175 M30

PROJECT PICTURE

CONCLUSION

As a conclusion, the CNC milling machines are easy to be operate if we know

and understand about the machine operation very well. Other than that, we need to

know about the programmer code which is G-code and M-code to operate the

machine. It is because this CNC milling machine are an automatically control

machine with the codes and it’s not a manually control machine. We have been

emphasizing on the safety when we are in the workshop.

Finally, we are managed to achieve our objective which to done an program

for an project that have been given by the lecturer. We have been told to prepare the

program to key-in the program into computer to see it simulation of the project before

it has been tested or key-in into the CNC milling machine. We need to done it

because we need to obtain an perfect project without any mistake because the CNC

milling machine is an automatic machine. At the end, our project simulation are

success and its perfect.

DISCUSSION

.: How to solve the problem when the result design difference as we want?

- Firstly, check again the code one by one

- Then, try to change the code when we fell wrong

- After that, try to make change repeat until the design correct same as we want