Cnc technology
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Jul 29, 2016
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About This Presentation
Cnc technology
Slide Content
11
CNCCNC
TECHNOLOGYTECHNOLOGY
Presented byPresented by
Mr.H.J.AhireMr.H.J.Ahire
M.Tech M/c DesignM.Tech M/c Design
Lecturer of Mechanical Dept.Lecturer of Mechanical Dept.
JMCE ChalisgaonJMCE Chalisgaon
CNCCNC
TECHNOLOGYTECHNOLOGY
Presented byPresented by
Mr.H.J.AhireMr.H.J.Ahire
M.Tech M/c DesignM.Tech M/c Design
Lecturer of Mechanical Dept.Lecturer of Mechanical Dept.
JMCE ChalisgaonJMCE Chalisgaon
22
HISTORYHISTORY
US Air Force commissioned MIT to develop the US Air Force commissioned MIT to develop the
first "numerically controlled" machine in 1949. It first "numerically controlled" machine in 1949. It
was demonstrated in 1952. was demonstrated in 1952.
At 1970-1972 first Computer Numeric Control At 1970-1972 first Computer Numeric Control
machines were developed.machines were developed.
Today, computer numerical control (CNC) Today, computer numerical control (CNC)
machines are found almost everywhere, from machines are found almost everywhere, from
small job shops in rural communities to small job shops in rural communities to
companies in large urban areas. companies in large urban areas.
HISTORYHISTORY
US Air Force commissioned MIT to develop the US Air Force commissioned MIT to develop the
first "numerically controlled" machine in 1949. It first "numerically controlled" machine in 1949. It
was demonstrated in 1952. was demonstrated in 1952.
At 1970-1972 first Computer Numeric Control At 1970-1972 first Computer Numeric Control
machines were developed.machines were developed.
Today, computer numerical control (CNC) Today, computer numerical control (CNC)
machines are found almost everywhere, from machines are found almost everywhere, from
small job shops in rural communities to small job shops in rural communities to
companies in large urban areas. companies in large urban areas.
33
DEFINITIONDEFINITION
In In CNC CNC ((Computer Numerical ControlComputer Numerical Control),), the the
instructions are stored as a program in a instructions are stored as a program in a
micro-computer attached to the machine. micro-computer attached to the machine.
The computer will also handle much of the The computer will also handle much of the
control logic of the machine, making it control logic of the machine, making it
more adaptable than earlier hard-wired more adaptable than earlier hard-wired
controllers.controllers.
DEFINITIONDEFINITION
In In CNC CNC ((Computer Numerical ControlComputer Numerical Control),), the the
instructions are stored as a program in a instructions are stored as a program in a
micro-computer attached to the machine. micro-computer attached to the machine.
The computer will also handle much of the The computer will also handle much of the
control logic of the machine, making it control logic of the machine, making it
more adaptable than earlier hard-wired more adaptable than earlier hard-wired
controllers.controllers.
44
CNC APPLICATIONSCNC APPLICATIONS
MachiningMachining
2.5D / 3D 2.5D / 3D
Turning ~ Lathes, Turning Centre Turning ~ Lathes, Turning Centre
Milling ~ Machining Centres Milling ~ Machining Centres
FormingForming
2D 2D
Plasma and Laser Cutting Plasma and Laser Cutting
Blanking, nibbling and punching Blanking, nibbling and punching
3D 3D
Rapid Prototyping Rapid Prototyping
CNC APPLICATIONSCNC APPLICATIONS
MachiningMachining
2.5D / 3D 2.5D / 3D
Turning ~ Lathes, Turning Centre Turning ~ Lathes, Turning Centre
Milling ~ Machining Centres Milling ~ Machining Centres
FormingForming
2D 2D
Plasma and Laser Cutting Plasma and Laser Cutting
Blanking, nibbling and punching Blanking, nibbling and punching
3D 3D
Rapid Prototyping Rapid Prototyping
55
SAMPLESAMPLE
CNC MACHINES CNC MACHINES
SAMPLESAMPLE
CNC MACHINES CNC MACHINES
66
CNC TURNINGCNC TURNING
CNC TURNINGCNC TURNING
77
CNC MILLINGCNC MILLING
CNC MILLINGCNC MILLING
88
CNC LASER CUTTINGCNC LASER CUTTING
CNC LASER CUTTINGCNC LASER CUTTING
99
CNC PLASMA CUTTINGCNC PLASMA CUTTING
CNC PLASMA CUTTINGCNC PLASMA CUTTING
1010
CNC PRESSCNC PRESS
CNC PRESSCNC PRESS
1111
CNC RAPID PROTOTYPINGCNC RAPID PROTOTYPING
CNC RAPID PROTOTYPINGCNC RAPID PROTOTYPING
1212
INDUSTRIES MOST AFFECTED INDUSTRIES MOST AFFECTED
by CNCby CNC
Aerospace Aerospace
Machinery Machinery
Electrical Electrical
Fabrication Fabrication
Automotive Automotive
Instrumentation Instrumentation
Mold making Mold making
INDUSTRIES MOST AFFECTED INDUSTRIES MOST AFFECTED
by CNCby CNC
Aerospace Aerospace
Machinery Machinery
Electrical Electrical
Fabrication Fabrication
Automotive Automotive
Instrumentation Instrumentation
Mold making Mold making
1313
SAMPLE PRODUCTSSAMPLE PRODUCTS
OF OF
CNC MANUFACTURINGCNC MANUFACTURING
SAMPLE PRODUCTSSAMPLE PRODUCTS
OF OF
CNC MANUFACTURINGCNC MANUFACTURING
1414
AUTOMOTIVE INDUSTRYAUTOMOTIVE INDUSTRY
Engine BlockEngine Block
AUTOMOTIVE INDUSTRYAUTOMOTIVE INDUSTRY
Engine BlockEngine Block
1515
AUTOMOTIVE INDUSTRY(Cont’d)AUTOMOTIVE INDUSTRY(Cont’d)
Different ProductsDifferent Products
AUTOMOTIVE INDUSTRY(Cont’d)AUTOMOTIVE INDUSTRY(Cont’d)
Different ProductsDifferent Products
1616
AEROSPACE INDUSTRYAEROSPACE INDUSTRY
Aircraft Turbine Machined by Aircraft Turbine Machined by
5-Axis CNC Milling Machine5-Axis CNC Milling Machine
AEROSPACE INDUSTRYAEROSPACE INDUSTRY
Aircraft Turbine Machined by Aircraft Turbine Machined by
5-Axis CNC Milling Machine5-Axis CNC Milling Machine
1717
CNC MOLD MAKINGCNC MOLD MAKING
CNC MOLD MAKINGCNC MOLD MAKING
1818
ELECTRONIC INDUSTRYELECTRONIC INDUSTRY
ELECTRONIC INDUSTRYELECTRONIC INDUSTRY
1919
RAPID PROTOTYPING RAPID PROTOTYPING
PRODUCTSPRODUCTS
RAPID PROTOTYPING RAPID PROTOTYPING
PRODUCTSPRODUCTS
2020
ADVANTAGES OF CNCADVANTAGES OF CNC
ADVANTAGES OF CNCADVANTAGES OF CNC
2121
Utilization of computers in Utilization of computers in
manufacturing applications has manufacturing applications has
proved to be one of the most proved to be one of the most
significant advantages & significant advantages &
developments over the last couple developments over the last couple
of decades in helping to improve of decades in helping to improve
the productivity and efficiency of the productivity and efficiency of
manufacturing systems.manufacturing systems.
Utilization of computers in Utilization of computers in
manufacturing applications has manufacturing applications has
proved to be one of the most proved to be one of the most
significant advantages & significant advantages &
developments over the last couple developments over the last couple
of decades in helping to improve of decades in helping to improve
the productivity and efficiency of the productivity and efficiency of
manufacturing systems.manufacturing systems.
2222
ADVANTAGES of CNCADVANTAGES of CNC
ProductivityProductivity
Machine utilisation is increased because Machine utilisation is increased because
more time is spent cutting and less time is more time is spent cutting and less time is
taken by positioning. taken by positioning.
Reduced setup time increases utilisation Reduced setup time increases utilisation
too. too.
ADVANTAGES of CNCADVANTAGES of CNC
ProductivityProductivity
Machine utilisation is increased because Machine utilisation is increased because
more time is spent cutting and less time is more time is spent cutting and less time is
taken by positioning. taken by positioning.
Reduced setup time increases utilisation Reduced setup time increases utilisation
too. too.
2323
PROFITPROFIT increases as increases as COSTCOST decreases decreases
and as and as PRODUCTIVITYPRODUCTIVITY increases. increases.
PRODUCTIVITY through PRODUCTIVITY through AUAUTOMATIONTOMATION
PROFITPROFIT increases as increases as COSTCOST decreases decreases
and as and as PRODUCTIVITYPRODUCTIVITY increases. increases.
PRODUCTIVITY through PRODUCTIVITY through AUAUTOMATIONTOMATION
2424
EFFICIENCY OF EFFICIENCY OF
MANUFACTURINGMANUFACTURING
COST = COST OF
MANUFACTURING AND
COST OF MATERIAL
HANDLING
PROFIT = INCOME - COST
PRODUCTIVITY =
AVERAGE OUTPUT PER
MAN-HOUR
EFFICIENCY OF EFFICIENCY OF
MANUFACTURINGMANUFACTURING
COST = COST OF
MANUFACTURING AND
COST OF MATERIAL
HANDLING
PROFIT = INCOME - COST
PRODUCTIVITY =
AVERAGE OUTPUT PER
MAN-HOUR
2525
ADVANTAGES of CNCADVANTAGES of CNC
QualityQuality
Parts are more accurate. Parts are more accurate.
Parts are more repeatable. Parts are more repeatable.
Less waste due to scrap. Less waste due to scrap.
ADVANTAGES of CNCADVANTAGES of CNC
QualityQuality
Parts are more accurate. Parts are more accurate.
Parts are more repeatable. Parts are more repeatable.
Less waste due to scrap. Less waste due to scrap.
2626
ADVANTAGES of CNCADVANTAGES of CNC
Reduced inventoryReduced inventory
Reduced setup time permits smaller Reduced setup time permits smaller
economic batch quantities. economic batch quantities.
Lower lead time allows lower stock levels. Lower lead time allows lower stock levels.
Lower stock levels reduce interest charges Lower stock levels reduce interest charges
and working capital requirements. and working capital requirements.
ADVANTAGES of CNCADVANTAGES of CNC
Reduced inventoryReduced inventory
Reduced setup time permits smaller Reduced setup time permits smaller
economic batch quantities. economic batch quantities.
Lower lead time allows lower stock levels. Lower lead time allows lower stock levels.
Lower stock levels reduce interest charges Lower stock levels reduce interest charges
and working capital requirements. and working capital requirements.
2727
ADVANTAGES of CNCADVANTAGES of CNC
Machining Complex shapesMachining Complex shapes
Slide movements under computer control. Slide movements under computer control.
Computer controller can calculate steps. Computer controller can calculate steps.
First NC machine built 1951 at MIT for First NC machine built 1951 at MIT for
aircraft skin milling. aircraft skin milling.
ADVANTAGES of CNCADVANTAGES of CNC
Machining Complex shapesMachining Complex shapes
Slide movements under computer control. Slide movements under computer control.
Computer controller can calculate steps. Computer controller can calculate steps.
First NC machine built 1951 at MIT for First NC machine built 1951 at MIT for
aircraft skin milling. aircraft skin milling.
2828
ADVANTAGES of CNCADVANTAGES of CNC
Management ControlManagement Control
CNC leads to CAD CNC leads to CAD
Process planning Process planning
Production planning Production planning
ADVANTAGES of CNCADVANTAGES of CNC
Management ControlManagement Control
CNC leads to CAD CNC leads to CAD
Process planning Process planning
Production planning Production planning
2929
DRAWBACKS of CNCDRAWBACKS of CNC
High capital cost High capital cost
Machine tools cost 10 Lac / machine Machine tools cost 10 Lac / machine
Retraining and recruitment of staff Retraining and recruitment of staff
New support facilities New support facilities
High maintenance requirementsHigh maintenance requirements
Not cost-effective for low-level production on Not cost-effective for low-level production on
simple partssimple parts
As geometric complexity or volume increases As geometric complexity or volume increases
CNC becomes more economicalCNC becomes more economical
Maintenance personnel must have both Maintenance personnel must have both
mechanical and electronics expertise mechanical and electronics expertise
DRAWBACKS of CNCDRAWBACKS of CNC
High capital cost High capital cost
Machine tools cost 10 Lac / machine Machine tools cost 10 Lac / machine
Retraining and recruitment of staff Retraining and recruitment of staff
New support facilities New support facilities
High maintenance requirementsHigh maintenance requirements
Not cost-effective for low-level production on Not cost-effective for low-level production on
simple partssimple parts
As geometric complexity or volume increases As geometric complexity or volume increases
CNC becomes more economicalCNC becomes more economical
Maintenance personnel must have both Maintenance personnel must have both
mechanical and electronics expertise mechanical and electronics expertise
3030
FUNDAMENTAL OF FUNDAMENTAL OF
METAL CUTTINGMETAL CUTTING
FUNDAMENTAL OF FUNDAMENTAL OF
METAL CUTTINGMETAL CUTTING
3131
The metal cutting operations The metal cutting operations (also (also
called machining)called machining) is one of the is one of the
most important manufacturing most important manufacturing
processes in industry today processes in industry today (as it (as it
was yesterday)was yesterday). .
The metal cutting operations The metal cutting operations (also (also
called machining)called machining) is one of the is one of the
most important manufacturing most important manufacturing
processes in industry today processes in industry today (as it (as it
was yesterday)was yesterday). .
3232
MACHINING MACHINING IS THE REMOVAL IS THE REMOVAL
OF MATERIALS IN FORMS OF OF MATERIALS IN FORMS OF
CHIPS FROM THE WORKPIECE CHIPS FROM THE WORKPIECE
BY SHEARING WITH A SHARP BY SHEARING WITH A SHARP
TOOL.TOOL.
MACHINING MACHINING IS THE REMOVAL IS THE REMOVAL
OF MATERIALS IN FORMS OF OF MATERIALS IN FORMS OF
CHIPS FROM THE WORKPIECE CHIPS FROM THE WORKPIECE
BY SHEARING WITH A SHARP BY SHEARING WITH A SHARP
TOOL.TOOL.
3333
The main function of a machine tool The main function of a machine tool
is to control the workpiece-cutting is to control the workpiece-cutting
tool positional relationship in such a tool positional relationship in such a
way as to achieve a desired way as to achieve a desired
geometric shape of the workpiece geometric shape of the workpiece
with sufficient dimensional with sufficient dimensional
accuracy.accuracy.
The main function of a machine tool The main function of a machine tool
is to control the workpiece-cutting is to control the workpiece-cutting
tool positional relationship in such a tool positional relationship in such a
way as to achieve a desired way as to achieve a desired
geometric shape of the workpiece geometric shape of the workpiece
with sufficient dimensional with sufficient dimensional
accuracy.accuracy.
3434
CLASSIFICATION OF MACHINE TOOLSCLASSIFICATION OF MACHINE TOOLS
THOSE USING
SINGLE
POINT
TOOLS
THOSE USING
MULTIPOIN
T TOOLS
THOSE USING
ABRASIVE
TOOLS
lathes
shapers
planers
boring m/c’s
etc.
drilling m/c’s
milling m/c’s
broaching m/c’s
hobbing m/c’s
etc.
grinding m/c’s
honing m/c’s
etc.
CLASSIFICATION OF MACHINE TOOLSCLASSIFICATION OF MACHINE TOOLS
THOSE USING
SINGLE
POINT
TOOLS
THOSE USING
MULTIPOIN
T TOOLS
THOSE USING
ABRASIVE
TOOLS
lathes
shapers
planers
boring m/c’s
etc.
drilling m/c’s
milling m/c’s
broaching m/c’s
hobbing m/c’s
etc.
grinding m/c’s
honing m/c’s
etc.
3535
BASIC COMPONENTS BASIC COMPONENTS
OF CNC SYSTEMSOF CNC SYSTEMS
BASIC COMPONENTS BASIC COMPONENTS
OF CNC SYSTEMSOF CNC SYSTEMS
3636
ISO MACHINE TOOL AXIS DEFINITIONISO MACHINE TOOL AXIS DEFINITION
ISO MACHINE TOOL AXIS DEFINITIONISO MACHINE TOOL AXIS DEFINITION
3737
ISO MACHINE TOOL AXES DEFINITIONS
AXISMACHINE TOOL WITH SPINDLE MACHINE TOOL WITH
NO SPINDLE
Zaxis of spindle,
(+Z) as tool goes away from the work piece
perpendicular to work
holding surface, (+Z) as
tool goes away from the
workpiece
MACHINE
TOOL WITH
ROTATING
WORKPIECE
MACHINE TOOL WITH
ROTATING TOOL
HORIZONT
AL AXIS
VERTICAL
AXIS
X radial and
parallel to
cross slide,
(+X) when
tool goes away
from the axis
of spindle
horizontal
and parallel
to work
holding
surface,
(+X) to the
right when
viewed
from
spindle
towards
work piece
horizontal
and parallel
to the work
holding
surface,
(+X) to the
right when
viewed
from
spindle
towards
column
parallel to and positive in
the principal direction of
cutting (primary motion)
Y apply right hand rules
ISO MACHINE TOOL AXES DEFINITIONS
AXISMACHINE TOOL WITH SPINDLE MACHINE TOOL WITH
NO SPINDLE
Zaxis of spindle,
(+Z) as tool goes away from the work piece
perpendicular to work
holding surface, (+Z) as
tool goes away from the
workpiece
MACHINE
TOOL WITH
ROTATING
WORKPIECE
MACHINE TOOL WITH
ROTATING TOOL
HORIZONT
AL AXIS
VERTICAL
AXIS
X radial and
parallel to
cross slide,
(+X) when
tool goes away
from the axis
of spindle
horizontal
and parallel
to work
holding
surface,
(+X) to the
right when
viewed
from
spindle
towards
work piece
horizontal
and parallel
to the work
holding
surface,
(+X) to the
right when
viewed
from
spindle
towards
column
parallel to and positive in
the principal direction of
cutting (primary motion)
Y apply right hand rules
3838
RIGHT HAND RULERIGHT HAND RULE
Vertical Machine Horizontal Vertical Machine Horizontal MachineMachine
RIGHT HAND RULERIGHT HAND RULE
Vertical Machine Horizontal Vertical Machine Horizontal MachineMachine
3939
STANDARD LATHE STANDARD LATHE
COORDINATE SYSTEMCOORDINATE SYSTEM
STANDARD LATHE STANDARD LATHE
COORDINATE SYSTEMCOORDINATE SYSTEM
4040
STANDARD MILLING MACHINESTANDARD MILLING MACHINE
COORDINATE SYSTEMCOORDINATE SYSTEM
STANDARD MILLING MACHINESTANDARD MILLING MACHINE
COORDINATE SYSTEMCOORDINATE SYSTEM
4141
The functions and motions such as;The functions and motions such as;
turning the spindle on and offturning the spindle on and off
setting cutting speedssetting cutting speeds
setting feed ratesetting feed rate
turning coolant on and offturning coolant on and off
moving tool with respect to workpiecemoving tool with respect to workpiece
are performed by Machine Control Unit (MCU) are performed by Machine Control Unit (MCU)
in NC machine tools.in NC machine tools.
The functions and motions such as;The functions and motions such as;
turning the spindle on and offturning the spindle on and off
setting cutting speedssetting cutting speeds
setting feed ratesetting feed rate
turning coolant on and offturning coolant on and off
moving tool with respect to workpiecemoving tool with respect to workpiece
are performed by Machine Control Unit (MCU) are performed by Machine Control Unit (MCU)
in NC machine tools.in NC machine tools.
4242
MACHINE TOOL MACHINE TOOL
AUTOMATIONAUTOMATION
MACHINE TOOL MACHINE TOOL
AUTOMATIONAUTOMATION
4343
CNC SYSTEM ELEMENTSCNC SYSTEM ELEMENTS
A typical CNC system consists of thA typical CNC system consists of the e
following six elements following six elements
Part program Part program
Program input device Program input device
Machine control unit Machine control unit
Drive system Drive system
Machine tool Machine tool
Feedback system Feedback system
CNC SYSTEM ELEMENTSCNC SYSTEM ELEMENTS
A typical CNC system consists of thA typical CNC system consists of the e
following six elements following six elements
Part program Part program
Program input device Program input device
Machine control unit Machine control unit
Drive system Drive system
Machine tool Machine tool
Feedback system Feedback system
4444
NC SYSTEM ELEMENTSNC SYSTEM ELEMENTS
NC SYSTEM ELEMENTSNC SYSTEM ELEMENTS
4545
OPERATIONAL FEATURES of OPERATIONAL FEATURES of
CNC MACHINESCNC MACHINES
OPERATIONAL FEATURES of OPERATIONAL FEATURES of
CNC MACHINESCNC MACHINES
4646
PART PROGRAMPART PROGRAM
A part program is a series of coded instructions required A part program is a series of coded instructions required
to produce a part. It controls the movement of the to produce a part. It controls the movement of the
machine tool and the on/off control of auxiliary functions machine tool and the on/off control of auxiliary functions
such as spindle rotation and coolant. The coded such as spindle rotation and coolant. The coded
instructions are composed of letters, numbers and instructions are composed of letters, numbers and
symbols and are arranged in a format of functional symbols and are arranged in a format of functional
blocks as in the following exampleblocks as in the following example
N10 G01 X5.0 Y2.5 F15.0N10 G01 X5.0 Y2.5 F15.0
| | | | | | | | | |
| | | | Feed rate (15 in/min) | | | | Feed rate (15 in/min)
| | | Y-coordinate (2.5") | | | Y-coordinate (2.5")
| | X-coordinate (5.0") | | X-coordinate (5.0")
| Linear interpolation mode | Linear interpolation mode
Sequence number Sequence number
PART PROGRAMPART PROGRAM
A part program is a series of coded instructions required A part program is a series of coded instructions required
to produce a part. It controls the movement of the to produce a part. It controls the movement of the
machine tool and the on/off control of auxiliary functions machine tool and the on/off control of auxiliary functions
such as spindle rotation and coolant. The coded such as spindle rotation and coolant. The coded
instructions are composed of letters, numbers and instructions are composed of letters, numbers and
symbols and are arranged in a format of functional symbols and are arranged in a format of functional
blocks as in the following exampleblocks as in the following example
N10 G01 X5.0 Y2.5 F15.0N10 G01 X5.0 Y2.5 F15.0
| | | | | | | | | |
| | | | Feed rate (15 in/min) | | | | Feed rate (15 in/min)
| | | Y-coordinate (2.5") | | | Y-coordinate (2.5")
| | X-coordinate (5.0") | | X-coordinate (5.0")
| Linear interpolation mode | Linear interpolation mode
Sequence number Sequence number
4747
PROGRAM INPUT DEVICEPROGRAM INPUT DEVICE
The program input device is the The program input device is the
mechanism for part programs to be mechanism for part programs to be
entered into the CNC control. Thentered into the CNC control. The moste most
commonly used program input devices are commonly used program input devices are
keyboardskeyboards,, punched tape reader, diskette punched tape reader, diskette
drivers, throgh RS 232 serial ports and drivers, throgh RS 232 serial ports and
networksnetworks. .
PROGRAM INPUT DEVICEPROGRAM INPUT DEVICE
The program input device is the The program input device is the
mechanism for part programs to be mechanism for part programs to be
entered into the CNC control. Thentered into the CNC control. The moste most
commonly used program input devices are commonly used program input devices are
keyboardskeyboards,, punched tape reader, diskette punched tape reader, diskette
drivers, throgh RS 232 serial ports and drivers, throgh RS 232 serial ports and
networksnetworks. .
4848
MACHINE CONTROL UNITMACHINE CONTROL UNIT
The machine control unit (MCU) is the heart of a CNC The machine control unit (MCU) is the heart of a CNC
system. It is used to perform the following functions: system. It is used to perform the following functions:
Read coded instructionsRead coded instructions
Decode coded instructions Decode coded instructions
Implement interpolations (linear, circular, and helical) to Implement interpolations (linear, circular, and helical) to
generate axis motion commands generate axis motion commands
Feed axis motion commands to the amplifier circuits for Feed axis motion commands to the amplifier circuits for
driving the axis mechanisms driving the axis mechanisms
Receive the feedback signals of position and speed for Receive the feedback signals of position and speed for
each drive axis each drive axis
Implement auxiliary control functions such as coolant or Implement auxiliary control functions such as coolant or
spindle on/off, and tool changespindle on/off, and tool change
MACHINE CONTROL UNITMACHINE CONTROL UNIT
The machine control unit (MCU) is the heart of a CNC The machine control unit (MCU) is the heart of a CNC
system. It is used to perform the following functions: system. It is used to perform the following functions:
Read coded instructionsRead coded instructions
Decode coded instructions Decode coded instructions
Implement interpolations (linear, circular, and helical) to Implement interpolations (linear, circular, and helical) to
generate axis motion commands generate axis motion commands
Feed axis motion commands to the amplifier circuits for Feed axis motion commands to the amplifier circuits for
driving the axis mechanisms driving the axis mechanisms
Receive the feedback signals of position and speed for Receive the feedback signals of position and speed for
each drive axis each drive axis
Implement auxiliary control functions such as coolant or Implement auxiliary control functions such as coolant or
spindle on/off, and tool changespindle on/off, and tool change
4949
TYPES of CNC CONTROL TYPES of CNC CONTROL
SYSTEMSSYSTEMS
Open-loop controlOpen-loop control
Closed-loop controlClosed-loop control
TYPES of CNC CONTROL TYPES of CNC CONTROL
SYSTEMSSYSTEMS
Open-loop controlOpen-loop control
Closed-loop controlClosed-loop control
5050
OPEN-LOOP CONTROL OPEN-LOOP CONTROL
SYSTEMSYSTEM
In open-loop control system step motors are In open-loop control system step motors are
usedused
Step motors are driven by electric pulsesStep motors are driven by electric pulses
Every pulse rotates the motor spindle through a Every pulse rotates the motor spindle through a
certain amountcertain amount
By counting the pulses, the amount of motion By counting the pulses, the amount of motion
can be controlledcan be controlled
No feedback signal for error correctionNo feedback signal for error correction
Lower positioning accuracy Lower positioning accuracy
OPEN-LOOP CONTROL OPEN-LOOP CONTROL
SYSTEMSYSTEM
In open-loop control system step motors are In open-loop control system step motors are
usedused
Step motors are driven by electric pulsesStep motors are driven by electric pulses
Every pulse rotates the motor spindle through a Every pulse rotates the motor spindle through a
certain amountcertain amount
By counting the pulses, the amount of motion By counting the pulses, the amount of motion
can be controlledcan be controlled
No feedback signal for error correctionNo feedback signal for error correction
Lower positioning accuracy Lower positioning accuracy
5151
CLOSED-LOOP CONTROL CLOSED-LOOP CONTROL
SYSTEMSSYSTEMS
In closed-loop control systems DC or AC In closed-loop control systems DC or AC
motors are usedmotors are used
Position transducers are used to generate Position transducers are used to generate
position feedback signals for error position feedback signals for error
correctioncorrection
Better accuracy can be achievedBetter accuracy can be achieved
More expensiveMore expensive
Suitable for large size machine toolsSuitable for large size machine tools
CLOSED-LOOP CONTROL CLOSED-LOOP CONTROL
SYSTEMSSYSTEMS
In closed-loop control systems DC or AC In closed-loop control systems DC or AC
motors are usedmotors are used
Position transducers are used to generate Position transducers are used to generate
position feedback signals for error position feedback signals for error
correctioncorrection
Better accuracy can be achievedBetter accuracy can be achieved
More expensiveMore expensive
Suitable for large size machine toolsSuitable for large size machine tools
CONTROLCONTROL
Desired path (Desired path (p, v, ap, v, a))
3-axis position control (encoder feedback)3-axis position control (encoder feedback)
Velocity control (tachometer feedback)Velocity control (tachometer feedback)
Torque control (current feedback)Torque control (current feedback)
Path generatorPath generator
Linear interpolationLinear interpolation
Circular interpolationCircular interpolation
Complex path interpolation (contouring)Complex path interpolation (contouring)
Desired path (Desired path (p, v, ap, v, a))
3-axis position control (encoder feedback)3-axis position control (encoder feedback)
Velocity control (tachometer feedback)Velocity control (tachometer feedback)
Torque control (current feedback)Torque control (current feedback)
Path generatorPath generator
Linear interpolationLinear interpolation
Circular interpolationCircular interpolation
Complex path interpolation (contouring)Complex path interpolation (contouring)
5353
DRIVE SYSTEMDRIVE SYSTEM
A drive system consists of amplifier A drive system consists of amplifier
circuits, circuits, steppingstepping motors motors or servomotors or servomotors
and ball lead-screws. The MCU feeds and ball lead-screws. The MCU feeds
control signals (position and speed) of control signals (position and speed) of
each axis to the amplifier circuits. The each axis to the amplifier circuits. The
control signals are augmented to actuate control signals are augmented to actuate
steppingstepping motors which in turn rotate the motors which in turn rotate the
ball lead-screws to position the machine ball lead-screws to position the machine
table. table.
DRIVE SYSTEMDRIVE SYSTEM
A drive system consists of amplifier A drive system consists of amplifier
circuits, circuits, steppingstepping motors motors or servomotors or servomotors
and ball lead-screws. The MCU feeds and ball lead-screws. The MCU feeds
control signals (position and speed) of control signals (position and speed) of
each axis to the amplifier circuits. The each axis to the amplifier circuits. The
control signals are augmented to actuate control signals are augmented to actuate
steppingstepping motors which in turn rotate the motors which in turn rotate the
ball lead-screws to position the machine ball lead-screws to position the machine
table. table.
5454
STEPPING MOTORSSTEPPING MOTORS
A stepping motor provides open-loop, digital
control of the position of a workpiece in a
numerical control machine. The drive unit
receives a direction input (cw or ccw) and pulse
inputs. For each pulse it receives, the drive unit
manipulates the motor voltage and current,
causing the motor shaft to rotate bya fixed angle
(one step). The lead screw converts the rotary
motion of the motor shaft into linear motion of
the workpiece .
STEPPING MOTORSSTEPPING MOTORS
A stepping motor provides open-loop, digital
control of the position of a workpiece in a
numerical control machine. The drive unit
receives a direction input (cw or ccw) and pulse
inputs. For each pulse it receives, the drive unit
manipulates the motor voltage and current,
causing the motor shaft to rotate bya fixed angle
(one step). The lead screw converts the rotary
motion of the motor shaft into linear motion of
the workpiece .
5555
STEPPING MOTORSSTEPPING MOTORS
STEPPING MOTORSSTEPPING MOTORS
5656
RECIRCULATING BALL RECIRCULATING BALL
SCREWSSCREWS
Transform rotational motion of the motor Transform rotational motion of the motor
intointo translationaltranslational motion of the nut attached to the motion of the nut attached to the
machine table.machine table.
RECIRCULATING BALL RECIRCULATING BALL
SCREWSSCREWS
Transform rotational motion of the motor Transform rotational motion of the motor
intointo translationaltranslational motion of the nut attached to the motion of the nut attached to the
machine table.machine table.
5757
RECIRCULATING BALL RECIRCULATING BALL
SCREWSSCREWS
Accuracy of CNC
machines depends on
their rigid
construction, care in
manufacturing, and
the use of ball screws
to almost eliminate
slop in the screws
used to move portions
of the machine.
RECIRCULATING BALL RECIRCULATING BALL
SCREWSSCREWS
Accuracy of CNC
machines depends on
their rigid
construction, care in
manufacturing, and
the use of ball screws
to almost eliminate
slop in the screws
used to move portions
of the machine.
COMPONENTS OF COMPONENTS OF
RECIRCULATING BALL SCREWSRECIRCULATING BALL SCREWS
Ball screwBall screw
Ball nut (anti-backlash)Ball nut (anti-backlash)
WaysWays
Linear bearingsLinear bearings
RECIRCULATING BALL SCREWSRECIRCULATING BALL SCREWS
Ball screwBall screw
Ball nut (anti-backlash)Ball nut (anti-backlash)
WaysWays
Linear bearingsLinear bearings
5959
6060
POSITIONINGPOSITIONING
The positioning resolution of a ball screw drive
mechanism is directly proportional to the
smallest angle that the motor can turn.
The smallest angle is controlled by the motor
step size.
Microsteps can be used to decrease the motor
step size.
CNC machines typically have resolutions of
0.0025 mm or better.
POSITIONINGPOSITIONING
The positioning resolution of a ball screw drive
mechanism is directly proportional to the
smallest angle that the motor can turn.
The smallest angle is controlled by the motor
step size.
Microsteps can be used to decrease the motor
step size.
CNC machines typically have resolutions of
0.0025 mm or better.
6161
MACHINE TOOLMACHINE TOOL
CNC controls are used to control various CNC controls are used to control various
types of machine tools. Regardless of types of machine tools. Regardless of
which type of machine tool is controlled, it which type of machine tool is controlled, it
always has a slide table and a spindle to always has a slide table and a spindle to
control of position and speed. The control of position and speed. The
machine table is controlled in the X and Y machine table is controlled in the X and Y
axes, while the spindle runs along the Z axes, while the spindle runs along the Z
axis. axis.
MACHINE TOOLMACHINE TOOL
CNC controls are used to control various CNC controls are used to control various
types of machine tools. Regardless of types of machine tools. Regardless of
which type of machine tool is controlled, it which type of machine tool is controlled, it
always has a slide table and a spindle to always has a slide table and a spindle to
control of position and speed. The control of position and speed. The
machine table is controlled in the X and Y machine table is controlled in the X and Y
axes, while the spindle runs along the Z axes, while the spindle runs along the Z
axis. axis.
6262
FEEDBACK SYSTEMFEEDBACK SYSTEM
The feedback system is also referred to as The feedback system is also referred to as
the measuring system. It uses position the measuring system. It uses position
and speed transducers to continuously and speed transducers to continuously
monitor the position at which the cutting monitor the position at which the cutting
tool is located at any particular time. The tool is located at any particular time. The
MCU uses the difference between MCU uses the difference between
reference signals and feedback signals to reference signals and feedback signals to
generate the control signals for correcting generate the control signals for correcting
position and speed errors. position and speed errors.
FEEDBACK SYSTEMFEEDBACK SYSTEM
The feedback system is also referred to as The feedback system is also referred to as
the measuring system. It uses position the measuring system. It uses position
and speed transducers to continuously and speed transducers to continuously
monitor the position at which the cutting monitor the position at which the cutting
tool is located at any particular time. The tool is located at any particular time. The
MCU uses the difference between MCU uses the difference between
reference signals and feedback signals to reference signals and feedback signals to
generate the control signals for correcting generate the control signals for correcting
position and speed errors. position and speed errors.
6363
CNC MACHINES FEEDBACK CNC MACHINES FEEDBACK
DEVICESDEVICES
CNC MACHINES FEEDBACK CNC MACHINES FEEDBACK
DEVICESDEVICES
6464
ENCODERSENCODERS
A device used to convert linear or
rotational position information into
an electrical output signal.
ENCODERSENCODERS
A device used to convert linear or
rotational position information into
an electrical output signal.
6565
ENCODERSENCODERS
ENCODERSENCODERS
6666
INDUSTRIAL APPLICATIONS of INDUSTRIAL APPLICATIONS of
ENCODERSENCODERS
INDUSTRIAL APPLICATIONS of INDUSTRIAL APPLICATIONS of
ENCODERSENCODERS
6767
RESOLVERSRESOLVERS
A resolver is a rotary
transformer that produces
an output signal that is a
function of the rotor
position.
RESOLVERSRESOLVERS
A resolver is a rotary
transformer that produces
an output signal that is a
function of the rotor
position.
6868
SERVOMOTOR with SERVOMOTOR with
RESOLVERRESOLVER
SERVOMOTOR with SERVOMOTOR with
RESOLVERRESOLVER
DRIVE MOTORSDRIVE MOTORS
DC servo motorsDC servo motors
AC servo motorsAC servo motors
Stepper motorsStepper motors
Hydraulic motorsHydraulic motors
DC servo motorsDC servo motors
AC servo motorsAC servo motors
Stepper motorsStepper motors
Hydraulic motorsHydraulic motors
POSITION FEEDBACKPOSITION FEEDBACK
Incremental encoderIncremental encoder
QuadratureQuadrature
Absolute encoderAbsolute encoder
ResolverResolver
TachometerTachometer
No feedback (open No feedback (open
loop)loop)
Incremental encoderIncremental encoder
QuadratureQuadrature
Absolute encoderAbsolute encoder
ResolverResolver
TachometerTachometer
No feedback (open No feedback (open
loop)loop)
7171
POTENTIOMETERSPOTENTIOMETERS
POTENTIOMETERSPOTENTIOMETERS
7272
POTENTIOMETERSPOTENTIOMETERS
POTENTIOMETERSPOTENTIOMETERS
CNC ProgrammingCNC Programming
ManualManual
Write code directlyWrite code directly
Computer-assistedComputer-assisted
Draw cutter pathDraw cutter path
CAD/CAMCAD/CAM
Draw the partDraw the part
Cutter path is generatedCutter path is generated
ManualManual
Write code directlyWrite code directly
Computer-assistedComputer-assisted
Draw cutter pathDraw cutter path
CAD/CAMCAD/CAM
Draw the partDraw the part
Cutter path is generatedCutter path is generated
7474
VELOCITY FEEDBACKVELOCITY FEEDBACK
Tachometers:
Electrical output is proportional to rate of
angular rotation.
Encoders, Resolvers, Potentiometers:
Number of pulses per time is proportional
to rate change of position.
VELOCITY FEEDBACKVELOCITY FEEDBACK
Tachometers:
Electrical output is proportional to rate of
angular rotation.
Encoders, Resolvers, Potentiometers:
Number of pulses per time is proportional
to rate change of position.
7575
CNC MACHINES CNC MACHINES
CUTTING TOOLS (CUTTERS)CUTTING TOOLS (CUTTERS)
CNC MACHINES CNC MACHINES
CUTTING TOOLS (CUTTERS)CUTTING TOOLS (CUTTERS)
7676
CNC CUTTERSCNC CUTTERS
Turning center cutters Turning center cutters
Machining center cuttersMachining center cutters
CNC CUTTERSCNC CUTTERS
Turning center cutters Turning center cutters
Machining center cuttersMachining center cutters
7777
TURNING CENTER CUTTERSTURNING CENTER CUTTERS
Types of cutters used on CNC turning
centers
Carbides (and other hard materials) insert
turning and boring tools
Ceramics
High Speed Steel (HSS) drills and taps
TURNING CENTER CUTTERSTURNING CENTER CUTTERS
Types of cutters used on CNC turning
centers
Carbides (and other hard materials) insert
turning and boring tools
Ceramics
High Speed Steel (HSS) drills and taps
7878
STANDART INSERT SHAPESSTANDART INSERT SHAPES
V – used for profiling, weakest
insert, 2 edges per side.
D – somewhat stronger, used for
profiling when the angle allows it,
2 edges per side.
T – commonly used for turning
because it has 3 edges per side.
C – popular insert because the
same holder can be used for
turning and facing. 2 edges per
side.
W – newest shape. Can turn and
face like the C, but 3 edges per
side.
S – Very strong, but mostly used
for chamfering because it won’t
cut a square shoulder. 4 edges
per side.
R – strongest insert but least
commonly used.
STANDART INSERT SHAPESSTANDART INSERT SHAPES
V – used for profiling, weakest
insert, 2 edges per side.
D – somewhat stronger, used for
profiling when the angle allows it,
2 edges per side.
T – commonly used for turning
because it has 3 edges per side.
C – popular insert because the
same holder can be used for
turning and facing. 2 edges per
side.
W – newest shape. Can turn and
face like the C, but 3 edges per
side.
S – Very strong, but mostly used
for chamfering because it won’t
cut a square shoulder. 4 edges
per side.
R – strongest insert but least
commonly used.
7979
TYPICAL TURNING,
THREADING and PARTING
TOOLS
TYPICAL TURNING,
THREADING and PARTING
TOOLS
8080
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLSTOOLS
Most machining centers
use some form of HSS or
carbide insert endmill as
the basic cutting tool.
Insert endmills cut many
times faster than HSS,
but the
HSS endmills leave a
better finish when side
cutting.
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLSTOOLS
Most machining centers
use some form of HSS or
carbide insert endmill as
the basic cutting tool.
Insert endmills cut many
times faster than HSS,
but the
HSS endmills leave a
better finish when side
cutting.
8181
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLS (cont’d)TOOLS (cont’d)
Facemills flatten large
surfaces quickly and
with an excellent
finish. Notice the
engine block being
finished in one pass
with a large cutter.
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLS (cont’d)TOOLS (cont’d)
Facemills flatten large
surfaces quickly and
with an excellent
finish. Notice the
engine block being
finished in one pass
with a large cutter.
8282
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLS (cont’d)TOOLS (cont’d)
Ball endmills (both
HSS and insert) are
used for a variety of
profiling operations
such as the mold
shown in the picture.
Slitting and side
cutters are used when
deep, narrow slots
must be cut.
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLS (cont’d)TOOLS (cont’d)
Ball endmills (both
HSS and insert) are
used for a variety of
profiling operations
such as the mold
shown in the picture.
Slitting and side
cutters are used when
deep, narrow slots
must be cut.
8383
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLS (cont’d)TOOLS (cont’d)
Drills, Taps, and Reamers
Common HSS tools such as
drills, taps, and reamers are
commonly used on CNC
machining centers. Note that a
spot drill is used instead of a
centerdrill. Also, spiral point or
gun taps are used for through
holes and spiral flute for blind
holes. Rarely are hand taps
used on a machining center.
MACHINING CENTER CUTTING MACHINING CENTER CUTTING
TOOLS (cont’d)TOOLS (cont’d)
Drills, Taps, and Reamers
Common HSS tools such as
drills, taps, and reamers are
commonly used on CNC
machining centers. Note that a
spot drill is used instead of a
centerdrill. Also, spiral point or
gun taps are used for through
holes and spiral flute for blind
holes. Rarely are hand taps
used on a machining center.
8484
TOOL HOLDERSTOOL HOLDERS
All cutting tools must be held in a holder
that fits in the spindle. These include end
mill holders (shown), collet holders, face
mill adapters, etc. Most machines in the
USA use a CAT taper which is a modified
NST 30, 40, or 50 taper that uses a pull
stud and a groove in the flange. The
machine pulls on the pull stud to hold the
holder in the spindle, and the groove in
the flange gives the automatic tool
changer something to hold onto. HSK tool
holders were designed a number of years
ago as an improvement to CAT tapers,
but they are gaining acceptance slowly.
TOOL HOLDERSTOOL HOLDERS
All cutting tools must be held in a holder
that fits in the spindle. These include end
mill holders (shown), collet holders, face
mill adapters, etc. Most machines in the
USA use a CAT taper which is a modified
NST 30, 40, or 50 taper that uses a pull
stud and a groove in the flange. The
machine pulls on the pull stud to hold the
holder in the spindle, and the groove in
the flange gives the automatic tool
changer something to hold onto. HSK tool
holders were designed a number of years
ago as an improvement to CAT tapers,
but they are gaining acceptance slowly.
8585
CNC PROGRAMMINGCNC PROGRAMMING
CNC PROGRAMMINGCNC PROGRAMMING
8686
CNC PROGRAMMINGCNC PROGRAMMING
Offline programmingOffline programming linked to CAD programs. linked to CAD programs.
Conversational programmingConversational programming by the operator. by the operator.
MDIMDI ~ Manual Data Input. ~ Manual Data Input.
Manual ControlManual Control using jog buttons or `electronic using jog buttons or `electronic
handwheel'. handwheel'.
Word-Address CodingWord-Address Coding using standard G-codes using standard G-codes
and M-codes. and M-codes.
CNC PROGRAMMINGCNC PROGRAMMING
Offline programmingOffline programming linked to CAD programs. linked to CAD programs.
Conversational programmingConversational programming by the operator. by the operator.
MDIMDI ~ Manual Data Input. ~ Manual Data Input.
Manual ControlManual Control using jog buttons or `electronic using jog buttons or `electronic
handwheel'. handwheel'.
Word-Address CodingWord-Address Coding using standard G-codes using standard G-codes
and M-codes. and M-codes.
8787
During secondary motion, either the tool During secondary motion, either the tool
moves relative to the workpiece or the moves relative to the workpiece or the
workpiece moves relative to the tool. In workpiece moves relative to the tool. In
NC programming, it is always assumed NC programming, it is always assumed
that the tool moves relative to the that the tool moves relative to the
workpiece no matter what the real workpiece no matter what the real
situation is.situation is.
Basics of NC Part Programming:Basics of NC Part Programming:
During secondary motion, either the tool During secondary motion, either the tool
moves relative to the workpiece or the moves relative to the workpiece or the
workpiece moves relative to the tool. In workpiece moves relative to the tool. In
NC programming, it is always assumed NC programming, it is always assumed
that the tool moves relative to the that the tool moves relative to the
workpiece no matter what the real workpiece no matter what the real
situation is.situation is.
Basics of NC Part Programming:Basics of NC Part Programming:
8888
The position of the tool is described The position of the tool is described
by using a Cartesian coordinate by using a Cartesian coordinate
system. If (0,0,0) position can be system. If (0,0,0) position can be
described by the operator, then it is described by the operator, then it is
called called floating zerofloating zero..
The position of the tool is described The position of the tool is described
by using a Cartesian coordinate by using a Cartesian coordinate
system. If (0,0,0) position can be system. If (0,0,0) position can be
described by the operator, then it is described by the operator, then it is
called called floating zerofloating zero..
8989
In defining the motion of the tool In defining the motion of the tool
from one point to another, from one point to another,
either either
absoluteabsolute positioningpositioning mode or mode or
incrementalincremental positioningpositioning mode mode
can be used.can be used.
In defining the motion of the tool In defining the motion of the tool
from one point to another, from one point to another,
either either
absoluteabsolute positioningpositioning mode or mode or
incrementalincremental positioningpositioning mode mode
can be used.can be used.
9090
1. 1. Absolute positioningAbsolute positioning. In this mode, the . In this mode, the
desired target position of the tool for a desired target position of the tool for a
particular move is given relative to the origin particular move is given relative to the origin
point of the program.point of the program.
2. 2. Incremental positioningIncremental positioning. In this mode, the . In this mode, the
next target position for the tool is given next target position for the tool is given
relative to the current tool relative to the current tool position.position.
1. 1. Absolute positioningAbsolute positioning. In this mode, the . In this mode, the
desired target position of the tool for a desired target position of the tool for a
particular move is given relative to the origin particular move is given relative to the origin
point of the program.point of the program.
2. 2. Incremental positioningIncremental positioning. In this mode, the . In this mode, the
next target position for the tool is given next target position for the tool is given
relative to the current tool relative to the current tool position.position.
9191
Structure of an NC Part Program:Structure of an NC Part Program:
Commands are input into the controller in
units called blocks or statements.
Block Format:
1. Fixed sequential format
2. Tab sequential format
3. Word address format
Structure of an NC Part Program:Structure of an NC Part Program:
Commands are input into the controller in
units called blocks or statements.
Block Format:
1. Fixed sequential format
2. Tab sequential format
3. Word address format
9292
EXAMPLE:EXAMPLE:
Assume that a drilling operation is to be
programmed as:
1. The tool is positioned at (25.4,12.5,0) by a
rapid movement.
2. The tool is then advanced -10 mm in the z
direction at a feed rate of 500 mm/min., with the
flood coolant on.
3.The is then retracted back 10 mm at the rapid
feed rate, and the coolant is turned off.
EXAMPLE:EXAMPLE:
Assume that a drilling operation is to be
programmed as:
1. The tool is positioned at (25.4,12.5,0) by a
rapid movement.
2. The tool is then advanced -10 mm in the z
direction at a feed rate of 500 mm/min., with the
flood coolant on.
3.The is then retracted back 10 mm at the rapid
feed rate, and the coolant is turned off.
9393
1. Fixed sequential format1. Fixed sequential format
0050 00 +0025400 +0012500 +0000000 0000 000050 00 +0025400 +0012500 +0000000 0000 00
0060 01 +0025400 +0012500 -0010000 0500 080060 01 +0025400 +0012500 -0010000 0500 08
0070 00 +0025400 +0012500 +0000000 0000 090070 00 +0025400 +0012500 +0000000 0000 09
2. Tab sequential format
0050 TAB 00 TAB +0025400 TAB +0012500 TAB +0000000 TAB TAB
0060 TAB 01 TAB TAB TAB -0010000 TAB 0500 TAB 08
0070 TAB 00 TAB TAB TAB -0000000 TAB 0000 TAB 09
3. Word address format
N50 G00 X25400 Y125 Z0 F0
N60 G01 Z-10000 F500 M08
N70 G00 Z0 M09
1. Fixed sequential format1. Fixed sequential format
0050 00 +0025400 +0012500 +0000000 0000 000050 00 +0025400 +0012500 +0000000 0000 00
0060 01 +0025400 +0012500 -0010000 0500 080060 01 +0025400 +0012500 -0010000 0500 08
0070 00 +0025400 +0012500 +0000000 0000 090070 00 +0025400 +0012500 +0000000 0000 09
2. Tab sequential format
0050 TAB 00 TAB +0025400 TAB +0012500 TAB +0000000 TAB TAB
0060 TAB 01 TAB TAB TAB -0010000 TAB 0500 TAB 08
0070 TAB 00 TAB TAB TAB -0000000 TAB 0000 TAB 09
3. Word address format
N50 G00 X25400 Y125 Z0 F0
N60 G01 Z-10000 F500 M08
N70 G00 Z0 M09
9494
Modal commandsModal commands: Commands issued in the : Commands issued in the
NC program that will stay in effect until it is NC program that will stay in effect until it is
changed by some other command, like, feed changed by some other command, like, feed
rate selection, coolant selection, etc.rate selection, coolant selection, etc.
Nonmodal commandsNonmodal commands: Commands that are : Commands that are
effective only when issued and whose effective only when issued and whose
effects are lost for subsequent commands, effects are lost for subsequent commands,
like, a dwell command which instructs the like, a dwell command which instructs the
tool to remain in a given configuration for a tool to remain in a given configuration for a
given amount of time.given amount of time.
Modal commandsModal commands: Commands issued in the : Commands issued in the
NC program that will stay in effect until it is NC program that will stay in effect until it is
changed by some other command, like, feed changed by some other command, like, feed
rate selection, coolant selection, etc.rate selection, coolant selection, etc.
Nonmodal commandsNonmodal commands: Commands that are : Commands that are
effective only when issued and whose effective only when issued and whose
effects are lost for subsequent commands, effects are lost for subsequent commands,
like, a dwell command which instructs the like, a dwell command which instructs the
tool to remain in a given configuration for a tool to remain in a given configuration for a
given amount of time.given amount of time.
9595
CNC PROGRAMMINGCNC PROGRAMMING
CNC PROGRAMMINGCNC PROGRAMMING
9696
INFORMATION NEEDED by a INFORMATION NEEDED by a
CNCCNC
1. Preparatory Information: units, incremental or absolute
positioning
2. Coordinates: X,Y,Z, RX,RY,RZ
3. Machining Parameters: Feed rate and spindle speed
4. Coolant Control: On/Off, Flood, Mist
5. Tool Control: Tool and tool parameters
6. Cycle Functions: Type of action required
7. Miscellaneous Control: Spindle on/off, direction of
rotation, stops for part movement
This information is conveyed to the machine through a set
of instructions arranged in a desired sequence – Program.
INFORMATION NEEDED by a INFORMATION NEEDED by a
CNCCNC
1. Preparatory Information: units, incremental or absolute
positioning
2. Coordinates: X,Y,Z, RX,RY,RZ
3. Machining Parameters: Feed rate and spindle speed
4. Coolant Control: On/Off, Flood, Mist
5. Tool Control: Tool and tool parameters
6. Cycle Functions: Type of action required
7. Miscellaneous Control: Spindle on/off, direction of
rotation, stops for part movement
This information is conveyed to the machine through a set
of instructions arranged in a desired sequence – Program.
9797
BLOCK FORMATBLOCK FORMAT
Sample BlockSample Block
N135 G01 X1.0 Y1.0 Z0.125 F5
Restrictions on CNC blocks
Each may contain only one tool move
Each may contain any number of non-tool move G-
codes
Each may contain only one feedrate
Each may contain only one specified tool or spindle
speed
The block numbers should be sequential
Both the program start flag and the program number
must be independent of all other commands (on
separate lines)
The data within a block should follow the sequence
shown in the above sample block
BLOCK FORMATBLOCK FORMAT
Sample BlockSample Block
N135 G01 X1.0 Y1.0 Z0.125 F5
Restrictions on CNC blocks
Each may contain only one tool move
Each may contain any number of non-tool move G-
codes
Each may contain only one feedrate
Each may contain only one specified tool or spindle
speed
The block numbers should be sequential
Both the program start flag and the program number
must be independent of all other commands (on
separate lines)
The data within a block should follow the sequence
shown in the above sample block
9898
WORD-ADDRESS CODINGWORD-ADDRESS CODING
N5 G90 G20N5 G90 G20
N10 M06 T3N10 M06 T3
N15 M03 S1250N15 M03 S1250
N20 G00 X1 Y1N20 G00 X1 Y1
N25 Z0.1N25 Z0.1
N30 G01 Z-0.125 F5N30 G01 Z-0.125 F5
N35 X3 Y2 F10N35 X3 Y2 F10
N40 G00 Z1N40 G00 Z1
N45 X0 Y0N45 X0 Y0
N50 M05N50 M05
N55 M30N55 M30
Example CNC ProgramExample CNC Program
Each instruction to the machine
consists of a letter followed by a
number.
Each letter is associated with a
specific type of action or piece of
information needed by the machine.
Letters used in Codes
N,G,X,Y,Z,A,B,C,I,J,K,F,S,T,R,M
WORD-ADDRESS CODINGWORD-ADDRESS CODING
N5 G90 G20N5 G90 G20
N10 M06 T3N10 M06 T3
N15 M03 S1250N15 M03 S1250
N20 G00 X1 Y1N20 G00 X1 Y1
N25 Z0.1N25 Z0.1
N30 G01 Z-0.125 F5N30 G01 Z-0.125 F5
N35 X3 Y2 F10N35 X3 Y2 F10
N40 G00 Z1N40 G00 Z1
N45 X0 Y0N45 X0 Y0
N50 M05N50 M05
N55 M30N55 M30
Example CNC ProgramExample CNC Program
Each instruction to the machine
consists of a letter followed by a
number.
Each letter is associated with a
specific type of action or piece of
information needed by the machine.
Letters used in Codes
N,G,X,Y,Z,A,B,C,I,J,K,F,S,T,R,M
9999
G & M CodesG & M Codes
N5 G90 G20N5 G90 G20
N10 M06 T3N10 M06 T3
N15 M03 S1250N15 M03 S1250
N20 G00 X1 Y1N20 G00 X1 Y1
N25 Z0.1N25 Z0.1
N30 G01 Z-0.125 F5N30 G01 Z-0.125 F5
N35 X3 Y2 F10N35 X3 Y2 F10
N40 G00 Z1N40 G00 Z1
N45 X0 Y0N45 X0 Y0
N50 M05N50 M05
N55 M30N55 M30
Example CNC ProgramExample CNC Program
• G-codes: Preparatory Functions
involve actual tool moves.
• M-codes: Miscellaneous
Functions – involve actions
necessary for machining (i.e.
spindle on/off, coolant on/off).
G & M CodesG & M Codes
N5 G90 G20N5 G90 G20
N10 M06 T3N10 M06 T3
N15 M03 S1250N15 M03 S1250
N20 G00 X1 Y1N20 G00 X1 Y1
N25 Z0.1N25 Z0.1
N30 G01 Z-0.125 F5N30 G01 Z-0.125 F5
N35 X3 Y2 F10N35 X3 Y2 F10
N40 G00 Z1N40 G00 Z1
N45 X0 Y0N45 X0 Y0
N50 M05N50 M05
N55 M30N55 M30
Example CNC ProgramExample CNC Program
• G-codes: Preparatory Functions
involve actual tool moves.
• M-codes: Miscellaneous
Functions – involve actions
necessary for machining (i.e.
spindle on/off, coolant on/off).
100100
G CodesG Codes
G00G00Rapid traverseRapid traverse
G01 Linear interpolationG01 Linear interpolation
G02G02 Circular interpolation, Circular interpolation,
CWCW
G03 Circular interpolation, G03 Circular interpolation,
CCWCCW
G04 DwellG04 Dwell
G08 AccelerationG08 Acceleration
G09 DecelerationG09 Deceleration
G17 X-Y PlaneG17 X-Y Plane
G18 Z-X PlaneG18 Z-X Plane
G19 Y-Z PlaneG19 Y-Z Plane
G20 Inch Units (G70)G20 Inch Units (G70)
G21 Metric Units (G71)G21 Metric Units (G71)
G40 Cutter compensation – G40 Cutter compensation –
cancelcancel
G41 Cutter compensation – G41 Cutter compensation –
leftleft
G42 Cutter compensation- G42 Cutter compensation-
rightright
G70 Inch formatG70 Inch format
G71 Metric formatG71 Metric format
G74 Full-circleG74 Full-circle programming programming
offoff
G75 Full-circle programming G75 Full-circle programming
onon
G80 Fixed-cycle cancelG80 Fixed-cycle cancel
G81-G89 Fixed cyclesG81-G89 Fixed cycles
G90 Absolute dimensionsG90 Absolute dimensions
G91 Incremental dimensionsG91 Incremental dimensions
G CodesG Codes
G00G00Rapid traverseRapid traverse
G01 Linear interpolationG01 Linear interpolation
G02G02 Circular interpolation, Circular interpolation,
CWCW
G03 Circular interpolation, G03 Circular interpolation,
CCWCCW
G04 DwellG04 Dwell
G08 AccelerationG08 Acceleration
G09 DecelerationG09 Deceleration
G17 X-Y PlaneG17 X-Y Plane
G18 Z-X PlaneG18 Z-X Plane
G19 Y-Z PlaneG19 Y-Z Plane
G20 Inch Units (G70)G20 Inch Units (G70)
G21 Metric Units (G71)G21 Metric Units (G71)
G40 Cutter compensation – G40 Cutter compensation –
cancelcancel
G41 Cutter compensation – G41 Cutter compensation –
leftleft
G42 Cutter compensation- G42 Cutter compensation-
rightright
G70 Inch formatG70 Inch format
G71 Metric formatG71 Metric format
G74 Full-circleG74 Full-circle programming programming
offoff
G75 Full-circle programming G75 Full-circle programming
onon
G80 Fixed-cycle cancelG80 Fixed-cycle cancel
G81-G89 Fixed cyclesG81-G89 Fixed cycles
G90 Absolute dimensionsG90 Absolute dimensions
G91 Incremental dimensionsG91 Incremental dimensions
101101
Modal G-CodesModal G-Codes
Most G-codes set theMost G-codes set the machine in a machine in a
“mode”“mode” which stays in effectwhich stays in effect until it is until it is
changed orchanged or cancelled by another Gcancelled by another G--code.code.
These commandsThese commands are called “modal”.are called “modal”.
Modal G-CodesModal G-Codes
Most G-codes set theMost G-codes set the machine in a machine in a
“mode”“mode” which stays in effectwhich stays in effect until it is until it is
changed orchanged or cancelled by another Gcancelled by another G--code.code.
These commandsThese commands are called “modal”.are called “modal”.
102102
Modal G-Code ListModal G-Code List
G00G00Rapid TransverseRapid Transverse
G01G01Linear InterpolationLinear Interpolation
G02G02Circular Interpolation, CWCircular Interpolation, CW
G03G03Circular Interpolation, Circular Interpolation,
CCWCCW
G17G17XY PlaneXY Plane
G18G18XZ PlaneXZ Plane
G19G19YZ PlaneYZ Plane
G20/G70 G20/G70 Inch unitsInch units
G21/G71 G21/G71 Metric UnitsMetric Units
G40 G40 Cutter compensation Cutter compensation
cancelcancel
G41 G41 Cutter compensation leftCutter compensation left
G42 G42 Cutter compensation rightCutter compensation right
G43 G43 Tool length compensation Tool length compensation
(plus)(plus)
G43G43Tool length Tool length
compensation compensation (plus)(plus)
G44G44Tool length Tool length
compensation compensation (minus)(minus)
G49G49Tool length Tool length
compensation compensation cancelcancel
G80G80Cancel canned cyclesCancel canned cycles
G81G81Drilling cycleDrilling cycle
G82G82Counter boring cycleCounter boring cycle
G83G83Deep hole drilling cycleDeep hole drilling cycle
G90G90Absolute positioningAbsolute positioning
G91G91Incremental positioningIncremental positioning
Modal G-Code ListModal G-Code List
G00G00Rapid TransverseRapid Transverse
G01G01Linear InterpolationLinear Interpolation
G02G02Circular Interpolation, CWCircular Interpolation, CW
G03G03Circular Interpolation, Circular Interpolation,
CCWCCW
G17G17XY PlaneXY Plane
G18G18XZ PlaneXZ Plane
G19G19YZ PlaneYZ Plane
G20/G70 G20/G70 Inch unitsInch units
G21/G71 G21/G71 Metric UnitsMetric Units
G40 G40 Cutter compensation Cutter compensation
cancelcancel
G41 G41 Cutter compensation leftCutter compensation left
G42 G42 Cutter compensation rightCutter compensation right
G43 G43 Tool length compensation Tool length compensation
(plus)(plus)
G43G43Tool length Tool length
compensation compensation (plus)(plus)
G44G44Tool length Tool length
compensation compensation (minus)(minus)
G49G49Tool length Tool length
compensation compensation cancelcancel
G80G80Cancel canned cyclesCancel canned cycles
G81G81Drilling cycleDrilling cycle
G82G82Counter boring cycleCounter boring cycle
G83G83Deep hole drilling cycleDeep hole drilling cycle
G90G90Absolute positioningAbsolute positioning
G91G91Incremental positioningIncremental positioning
103103
M CodesM Codes
M00 M00 Program stopProgram stop
M01 M01 Optional program stopOptional program stop
M02 M02 Program endProgram end
M03 M03 Spindle on clockwiseSpindle on clockwise
M04 M04 Spindle on counterclockwiseSpindle on counterclockwise
M05 M05 Spindle stopSpindle stop
M06 M06 Tool changeTool change
M08 M08 Coolant onCoolant on
M09 M09 Coolant offCoolant off
M10 M10 Clamps onClamps on
M11 M11 Clamps offClamps off
M30 M30 Program stop, reset to startProgram stop, reset to start
M CodesM Codes
M00 M00 Program stopProgram stop
M01 M01 Optional program stopOptional program stop
M02 M02 Program endProgram end
M03 M03 Spindle on clockwiseSpindle on clockwise
M04 M04 Spindle on counterclockwiseSpindle on counterclockwise
M05 M05 Spindle stopSpindle stop
M06 M06 Tool changeTool change
M08 M08 Coolant onCoolant on
M09 M09 Coolant offCoolant off
M10 M10 Clamps onClamps on
M11 M11 Clamps offClamps off
M30 M30 Program stop, reset to startProgram stop, reset to start
104104
N CodesN Codes
Gives anGives an identifying number for eachidentifying number for each block block
of information.of information.
It is generally good practice toIt is generally good practice to increment increment
each block number byeach block number by 5 or 10 to allow 5 or 10 to allow
additionaladditional blocks to be inserted if futureblocks to be inserted if future
changes are required.changes are required.
N CodesN Codes
Gives anGives an identifying number for eachidentifying number for each block block
of information.of information.
It is generally good practice toIt is generally good practice to increment increment
each block number byeach block number by 5 or 10 to allow 5 or 10 to allow
additionaladditional blocks to be inserted if futureblocks to be inserted if future
changes are required.changes are required.
105105
X,Y, and Z CodesX,Y, and Z Codes
X, Y, and Z X, Y, and Z codes are used tocodes are used to specify the specify the
coordinate axis.coordinate axis.
Number following the codeNumber following the code defines the defines the
coordinate at the endcoordinate at the end of the move relative of the move relative
to anto an incremental or absoluteincremental or absolute reference reference
point.point.
X,Y, and Z CodesX,Y, and Z Codes
X, Y, and Z X, Y, and Z codes are used tocodes are used to specify the specify the
coordinate axis.coordinate axis.
Number following the codeNumber following the code defines the defines the
coordinate at the endcoordinate at the end of the move relative of the move relative
to anto an incremental or absoluteincremental or absolute reference reference
point.point.
106106
I,J, and K CodesI,J, and K Codes
I, J, and K I, J, and K codes are used tocodes are used to specify the specify the
coordinate axiscoordinate axis when defining the center when defining the center
of aof a circle.circle.
Number following the codeNumber following the code defines the defines the
respective coordinaterespective coordinate for the center of the for the center of the
circle.circle.
I,J, and K CodesI,J, and K Codes
I, J, and K I, J, and K codes are used tocodes are used to specify the specify the
coordinate axiscoordinate axis when defining the center when defining the center
of aof a circle.circle.
Number following the codeNumber following the code defines the defines the
respective coordinaterespective coordinate for the center of the for the center of the
circle.circle.
107107
FF,,SS, and , and TT Codes Codes
F-codeF-code: used to specify the feed: used to specify the feed raterate
S-codeS-code: used to specify the: used to specify the spindle speedspindle speed
T-codeT-code: used to specify the tool: used to specify the tool
identification number associatedidentification number associated with the with the
tool to be used intool to be used in subsequent operations.subsequent operations.
FF,,SS, and , and TT Codes Codes
F-codeF-code: used to specify the feed: used to specify the feed raterate
S-codeS-code: used to specify the: used to specify the spindle speedspindle speed
T-codeT-code: used to specify the tool: used to specify the tool
identification number associatedidentification number associated with the with the
tool to be used intool to be used in subsequent operations.subsequent operations.
108108
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
Format: N_ G01 X_ Y_ Z_ F_Format: N_ G01 X_ Y_ Z_ F_
Linear Interpolation results in a straight Linear Interpolation results in a straight
line feedline feed move.move.
Unless tool compensation is used, theUnless tool compensation is used, the
coordinates arecoordinates are associated with the associated with the
centerline of the tool.centerline of the tool.
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
Format: N_ G01 X_ Y_ Z_ F_Format: N_ G01 X_ Y_ Z_ F_
Linear Interpolation results in a straight Linear Interpolation results in a straight
line feedline feed move.move.
Unless tool compensation is used, theUnless tool compensation is used, the
coordinates arecoordinates are associated with the associated with the
centerline of the tool.centerline of the tool.
109109
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
. As an example, for the motion that occurs in . As an example, for the motion that occurs in x-x-
y plane with the same maximum speed for the x- y plane with the same maximum speed for the x-
and y-axis, initial motion is at an angle of 45o to and y-axis, initial motion is at an angle of 45o to
the axes until motion in one of the axes until motion in one of
the axes is completed and then the balance of the axes is completed and then the balance of
the motion occurs in the other axis. This is called the motion occurs in the other axis. This is called
point-to-point motionpoint-to-point motion..
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
. As an example, for the motion that occurs in . As an example, for the motion that occurs in x-x-
y plane with the same maximum speed for the x- y plane with the same maximum speed for the x-
and y-axis, initial motion is at an angle of 45o to and y-axis, initial motion is at an angle of 45o to
the axes until motion in one of the axes until motion in one of
the axes is completed and then the balance of the axes is completed and then the balance of
the motion occurs in the other axis. This is called the motion occurs in the other axis. This is called
point-to-point motionpoint-to-point motion..
110110
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
G01 is another preparatory function to specify
that the tool should be moved to a specified
location along a straight line path. It is referred
to as linear interpolation.
This function is typically used to specify
machining of straight features such as turning
a cylindrical surface in turning, cutting a slot in
milling, etc.
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
G01 is another preparatory function to specify
that the tool should be moved to a specified
location along a straight line path. It is referred
to as linear interpolation.
This function is typically used to specify
machining of straight features such as turning
a cylindrical surface in turning, cutting a slot in
milling, etc.
111111
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
5
10
15
20
25
5 10 15 20 25 30
A
C
Linear interpolation from A to C
N10 G01 X30000 Y20000 F2500
Application of Some CodesApplication of Some Codes
G01 Linear InterpolationG01 Linear Interpolation
5
10
15
20
25
5 10 15 20 25 30
A
C
Linear interpolation from A to C
N10 G01 X30000 Y20000 F2500
112112
N10 N10 G00 X1 G00 X1 ZZ11
NN115 Z0.15 Z0.1
NN2020 G01 Z-0.125 F5 G01 Z-0.125 F5
NN225 5 X2 Z2 X2 Z2 F10F10
G01 Linear InterpolationG01 Linear Interpolation
X
Z
N10 N10 G00 X1 G00 X1 ZZ11
NN115 Z0.15 Z0.1
NN2020 G01 Z-0.125 F5 G01 Z-0.125 F5
NN225 5 X2 Z2 X2 Z2 F10F10
G01 Linear InterpolationG01 Linear Interpolation
X
Z
113113
G02 Circular InterpolationG02 Circular Interpolation
G02 is also a preparatory function to specify that G02 is also a preparatory function to specify that
the tool should be moved to a specified location the tool should be moved to a specified location
along a circular path in a clockwise direction. In along a circular path in a clockwise direction. In
order to specify the path to the MCU, the end order to specify the path to the MCU, the end
point of the arc and the location of the center of point of the arc and the location of the center of
the arc should be specified. Within the block in the arc should be specified. Within the block in
which the G02 code is programmed, the center which the G02 code is programmed, the center
of the arc is given by specifying its location of the arc is given by specifying its location
relative to the start of the arc. relative to the start of the arc.
G02 Circular InterpolationG02 Circular Interpolation
G02 is also a preparatory function to specify that G02 is also a preparatory function to specify that
the tool should be moved to a specified location the tool should be moved to a specified location
along a circular path in a clockwise direction. In along a circular path in a clockwise direction. In
order to specify the path to the MCU, the end order to specify the path to the MCU, the end
point of the arc and the location of the center of point of the arc and the location of the center of
the arc should be specified. Within the block in the arc should be specified. Within the block in
which the G02 code is programmed, the center which the G02 code is programmed, the center
of the arc is given by specifying its location of the arc is given by specifying its location
relative to the start of the arc. relative to the start of the arc.
114114
G02 Circular Interpolation (CW)G02 Circular Interpolation (CW)
The G02 commandThe G02 command requiresrequires
an endpoint and a radiusan endpoint and a radius inin
order to cut the arc.order to cut the arc.
I,J, and K are relativeI,J, and K are relative to the to the
start point.start point.
N_ G02 X2 Y1 I0 J-1 F10N_ G02 X2 Y1 I0 J-1 F10
oror
N_ G02 X2 Y1 R1N_ G02 X2 Y1 R1
G02 Circular Interpolation (CW)G02 Circular Interpolation (CW)
The G02 commandThe G02 command requiresrequires
an endpoint and a radiusan endpoint and a radius inin
order to cut the arc.order to cut the arc.
I,J, and K are relativeI,J, and K are relative to the to the
start point.start point.
N_ G02 X2 Y1 I0 J-1 F10N_ G02 X2 Y1 I0 J-1 F10
oror
N_ G02 X2 Y1 R1N_ G02 X2 Y1 R1
115115
G02 Circular Interpolation (CW)G02 Circular Interpolation (CW)
5
10
15
20
25
5 10 15 20 25 30
C
C
Circular interpolation from A to B
about a circle centered at C
N10 G02 X20000 Y10000
I5000 J15000 F2500
A
B
I=5
J=15
G02 Circular Interpolation (CW)G02 Circular Interpolation (CW)
5
10
15
20
25
5 10 15 20 25 30
C
C
Circular interpolation from A to B
about a circle centered at C
N10 G02 X20000 Y10000
I5000 J15000 F2500
A
B
I=5
J=15
116116
The sequence of some machining operations
is may be the same for any part and for any
machine. For example, drilling a hole involves
the following steps:
Position the tool above the point where the
hole will be drilled
Set the correct spindle speed
Feed the tool into the workpiece at a
controlled feed rate to a predetermined depth
Retract the tool at a rapid rate to just above
the point where the hole started
Canned Cycles
The sequence of some machining operations
is may be the same for any part and for any
machine. For example, drilling a hole involves
the following steps:
Position the tool above the point where the
hole will be drilled
Set the correct spindle speed
Feed the tool into the workpiece at a
controlled feed rate to a predetermined depth
Retract the tool at a rapid rate to just above
the point where the hole started
Canned Cycles
117117
Some Commonly Used Canned Cycle
CodeFunction Down feedAt bottomRetracti
on
G81Drilling Continuous
feed
No actionRapid
G82Spot face,
counterbore
Continuous
feed
Dwell Rapid
G83Deep hole drillingPeck No actionRapid
G84 Tapping Continuous
feed
Reverse
spindle
Feed
rate
G85Through boring(in
& out)
Continuous
feed
No actionFeed
rate
G86Through boring(in
only)
Continuous
feed
Stop
spindle
Rapid
Some Commonly Used Canned Cycle
CodeFunction Down feedAt bottomRetracti
on
G81Drilling Continuous
feed
No actionRapid
G82Spot face,
counterbore
Continuous
feed
Dwell Rapid
G83Deep hole drillingPeck No actionRapid
G84 Tapping Continuous
feed
Reverse
spindle
Feed
rate
G85Through boring(in
& out)
Continuous
feed
No actionFeed
rate
G86Through boring(in
only)
Continuous
feed
Stop
spindle
Rapid
118118
G81 ILLUSTRATIONG81 ILLUSTRATION
G81 ILLUSTRATIONG81 ILLUSTRATION
119119
Three Main parts of a CNC Three Main parts of a CNC
programprogram
N5 G90 G2N5 G90 G211 (Absolute units, (Absolute units, metricmetric))
N10 M06 T2 N10 M06 T2 (Stop for tool change, use (Stop for tool change, use
tool # 2)tool # 2)
N15 M03 S1200 N15 M03 S1200 (Turn the spindle on CW to (Turn the spindle on CW to
1200 rpm)1200 rpm)
Part 1- Program PetupPart 1- Program Petup
Three Main parts of a CNC Three Main parts of a CNC
programprogram
N5 G90 G2N5 G90 G211 (Absolute units, (Absolute units, metricmetric))
N10 M06 T2 N10 M06 T2 (Stop for tool change, use (Stop for tool change, use
tool # 2)tool # 2)
N15 M03 S1200 N15 M03 S1200 (Turn the spindle on CW to (Turn the spindle on CW to
1200 rpm)1200 rpm)
Part 1- Program PetupPart 1- Program Petup
120120
Three Main parts of a CNC Three Main parts of a CNC
programprogram
N20 G00 X1 Y1 N20 G00 X1 Y1 (Rapid to X1,Y1 from origin (Rapid to X1,Y1 from origin
point)point)
N25 Z0.125 N25 Z0.125 (Rapid down to Z0.125)(Rapid down to Z0.125)
N30 G01 Z-0.125 FN30 G01 Z-0.125 F100100 (Feed down to Z-0.125 at (Feed down to Z-0.125 at
100 mm/100 mm/mminin))
N35 G01 X2 Y2 N35 G01 X2 Y2 (Feed diagonally to X2,Y2)(Feed diagonally to X2,Y2)
N40 G00 Z1 N40 G00 Z1 (Rapid up to Z1)(Rapid up to Z1)
N45 X0 Y0 N45 X0 Y0 (Rapid to X0,Y0)(Rapid to X0,Y0)
Part 2- Chip RemovalPart 2- Chip Removal
Three Main parts of a CNC Three Main parts of a CNC
programprogram
N20 G00 X1 Y1 N20 G00 X1 Y1 (Rapid to X1,Y1 from origin (Rapid to X1,Y1 from origin
point)point)
N25 Z0.125 N25 Z0.125 (Rapid down to Z0.125)(Rapid down to Z0.125)
N30 G01 Z-0.125 FN30 G01 Z-0.125 F100100 (Feed down to Z-0.125 at (Feed down to Z-0.125 at
100 mm/100 mm/mminin))
N35 G01 X2 Y2 N35 G01 X2 Y2 (Feed diagonally to X2,Y2)(Feed diagonally to X2,Y2)
N40 G00 Z1 N40 G00 Z1 (Rapid up to Z1)(Rapid up to Z1)
N45 X0 Y0 N45 X0 Y0 (Rapid to X0,Y0)(Rapid to X0,Y0)
Part 2- Chip RemovalPart 2- Chip Removal
121121
Three Main parts of a CNC Three Main parts of a CNC
programprogram
N50 M05 N50 M05 (Turn the spindle off)(Turn the spindle off)
N55 MN55 M000 0 ((PProgramrogram stop stop))
Part 3- System ShutdownPart 3- System Shutdown
Three Main parts of a CNC Three Main parts of a CNC
programprogram
N50 M05 N50 M05 (Turn the spindle off)(Turn the spindle off)
N55 MN55 M000 0 ((PProgramrogram stop stop))
Part 3- System ShutdownPart 3- System Shutdown
122122
EXAMPLE OPERATION on CNC EXAMPLE OPERATION on CNC
MILLING MACHINEMILLING MACHINE
EXAMPLE OPERATION on CNC EXAMPLE OPERATION on CNC
MILLING MACHINEMILLING MACHINE
123123
G-CODE PROGRAMG-CODE PROGRAM
First pass : conventional mill to
a depth of 0.125 around edge
profile. Tool 1 is a ½ inch dia.
end mill.
%
:1002
N5 G90 G20
N10 M06 T1
N15 M03 S1200
N20 G00 X0.125 Y0.125
N30 Z0.125
N35 G01 Z-0.125 F5
N40 X3.875
N45 Y4.125
N50 X0.125
N55 Y0.125
G-CODE PROGRAMG-CODE PROGRAM
First pass : conventional mill to
a depth of 0.125 around edge
profile. Tool 1 is a ½ inch dia.
end mill.
%
:1002
N5 G90 G20
N10 M06 T1
N15 M03 S1200
N20 G00 X0.125 Y0.125
N30 Z0.125
N35 G01 Z-0.125 F5
N40 X3.875
N45 Y4.125
N50 X0.125
N55 Y0.125
124124
Second pass:
conventional mill to a
depth of 0.25 around
edge profile.
N35 Z-0.250
N40 X3.875
N45 Y4.125
N50 X0.125
N55 Y0.125
N60 Z0.125
Second pass:
conventional mill to a
depth of 0.25 around
edge profile.
N35 Z-0.250
N40 X3.875
N45 Y4.125
N50 X0.125
N55 Y0.125
N60 Z0.125
125125
Third pass:
conventional mill to a
depth of 0.125 around
pocket profile.
N65 G00 X1.25 Y1.0
N70 G01 Z-0.125 F5
N75 X1.75
N80 Y2.5
N85 X1.25
N90 Y1.0
N95 Z0.125
Third pass:
conventional mill to a
depth of 0.125 around
pocket profile.
N65 G00 X1.25 Y1.0
N70 G01 Z-0.125 F5
N75 X1.75
N80 Y2.5
N85 X1.25
N90 Y1.0
N95 Z0.125
126126
Fourth pass: climb
mill to a depth of
0.125 across
remaining material.
N100 Y2.125
N105 X2.625
N110 Z0.125
N115 G00 X-5 Y-5 Z5
N120 M05
N125 M30
Fourth pass: climb
mill to a depth of
0.125 across
remaining material.
N100 Y2.125
N105 X2.625
N110 Z0.125
N115 G00 X-5 Y-5 Z5
N120 M05
N125 M30
127127
Advanced features:Advanced features:
Execution of the part of the program in a Execution of the part of the program in a
rotated or mirrored position.rotated or mirrored position.
Ability to scale the program and produce Ability to scale the program and produce
larger or smaller programs.larger or smaller programs.
Three dimensional circular interpolation Three dimensional circular interpolation
which produces a helical shape.which produces a helical shape.
Parabolic and cubic interpolation.Parabolic and cubic interpolation.
Advanced features:Advanced features:
Execution of the part of the program in a Execution of the part of the program in a
rotated or mirrored position.rotated or mirrored position.
Ability to scale the program and produce Ability to scale the program and produce
larger or smaller programs.larger or smaller programs.
Three dimensional circular interpolation Three dimensional circular interpolation
which produces a helical shape.which produces a helical shape.
Parabolic and cubic interpolation.Parabolic and cubic interpolation.
128128
Program Loading:
Through keyboard
Through punched tape reader
Through diskette drive
Through RS 232 serial port
Through network interface card
Program Loading:
Through keyboard
Through punched tape reader
Through diskette drive
Through RS 232 serial port
Through network interface card
129129
A system in which a central computer
downloads the NC programs block by block
to many NC machine tools simultaneously is
called Direct Numerical Control (DNC)
system.
Direct Numerical Control (DNC):
A system in which a central computer
downloads the NC programs block by block
to many NC machine tools simultaneously is
called Direct Numerical Control (DNC)
system.
Direct Numerical Control (DNC):
130130
This system used to work with the early NC
machine tools which can not read more than a
block of information at a time. The central
computer feed the program information one
block at a time. When the machine execute the
information, the next block of information would
be fed.
Direct Numerical Control (DNC):
This system used to work with the early NC
machine tools which can not read more than a
block of information at a time. The central
computer feed the program information one
block at a time. When the machine execute the
information, the next block of information would
be fed.
Direct Numerical Control (DNC):
131131
Distributed NC is known by the same acronym Distributed NC is known by the same acronym
as Direct Numerical Control (DNC). After the as Direct Numerical Control (DNC). After the
introduction of CNC, the machine tools have introduction of CNC, the machine tools have
had the capability of storing large amount of had the capability of storing large amount of
information. Therefore, there have been no information. Therefore, there have been no
need to have drip feed information system, like, need to have drip feed information system, like,
Direct Numerical Control. Instead, Distributed Direct Numerical Control. Instead, Distributed
Numerical Control is introduced. In such a Numerical Control is introduced. In such a
system, a host computer communicate with system, a host computer communicate with
many CNC machine tools via networks and many CNC machine tools via networks and
download or upload programs.download or upload programs.
Distributed Numerical Control (DNC):
Distributed NC is known by the same acronym Distributed NC is known by the same acronym
as Direct Numerical Control (DNC). After the as Direct Numerical Control (DNC). After the
introduction of CNC, the machine tools have introduction of CNC, the machine tools have
had the capability of storing large amount of had the capability of storing large amount of
information. Therefore, there have been no information. Therefore, there have been no
need to have drip feed information system, like, need to have drip feed information system, like,
Direct Numerical Control. Instead, Distributed Direct Numerical Control. Instead, Distributed
Numerical Control is introduced. In such a Numerical Control is introduced. In such a
system, a host computer communicate with system, a host computer communicate with
many CNC machine tools via networks and many CNC machine tools via networks and
download or upload programs.download or upload programs.
Distributed Numerical Control (DNC):
132132
With Distributed Numerical Control systems, it With Distributed Numerical Control systems, it
is possible to monitor the activities in individual is possible to monitor the activities in individual
CNC machine tools on host computer. CNC machine tools on host computer.
Therefore, better shop floor control can be Therefore, better shop floor control can be
achieved.achieved.
Distributed Numerical Control (DNC):
With Distributed Numerical Control systems, it With Distributed Numerical Control systems, it
is possible to monitor the activities in individual is possible to monitor the activities in individual
CNC machine tools on host computer. CNC machine tools on host computer.
Therefore, better shop floor control can be Therefore, better shop floor control can be
achieved.achieved.
Distributed Numerical Control (DNC):
133133
NC program preparation may be tedious and NC program preparation may be tedious and
difficult if the part to be machined has a difficult if the part to be machined has a
complex geometry. The main difficulty is to find complex geometry. The main difficulty is to find
out the cutter locations during the machining. out the cutter locations during the machining.
Computers may be used to assist the Computers may be used to assist the
programmers in preparing the NC codes.programmers in preparing the NC codes.
Computer Aided Part Programming:
NC program preparation may be tedious and NC program preparation may be tedious and
difficult if the part to be machined has a difficult if the part to be machined has a
complex geometry. The main difficulty is to find complex geometry. The main difficulty is to find
out the cutter locations during the machining. out the cutter locations during the machining.
Computers may be used to assist the Computers may be used to assist the
programmers in preparing the NC codes.programmers in preparing the NC codes.
Computer Aided Part Programming:
134134
Advantages of applying computer-aided part Advantages of applying computer-aided part
programming include the following:programming include the following:
1. It reduces the manual calculations 1. It reduces the manual calculations
involves in determining the geometric involves in determining the geometric
characteristics of the part.characteristics of the part.
It provides the cutter path simulation.It provides the cutter path simulation.
It provides tool collision checking.It provides tool collision checking.
It shortens the program preparation time.It shortens the program preparation time.
It makes the program preparation easier.It makes the program preparation easier.
Advantages of applying computer-aided part Advantages of applying computer-aided part
programming include the following:programming include the following:
1. It reduces the manual calculations 1. It reduces the manual calculations
involves in determining the geometric involves in determining the geometric
characteristics of the part.characteristics of the part.
It provides the cutter path simulation.It provides the cutter path simulation.
It provides tool collision checking.It provides tool collision checking.
It shortens the program preparation time.It shortens the program preparation time.
It makes the program preparation easier.It makes the program preparation easier.
135135
The Aerospace Industries Association The Aerospace Industries Association
sponsored the work that led to the first part sponsored the work that led to the first part
programming language, developed in MIT in programming language, developed in MIT in
1955.1955.
This was called:This was called: Automatically Programmed Automatically Programmed
ToolsTools (APT). (APT).
APT is an English like simple programming APT is an English like simple programming
language which basically produce the language which basically produce the Cutter Cutter
LocationLocation (CL) data. (CL) data.
Using the cutter location data, the program can Using the cutter location data, the program can
generate the actual NC codes by using a generate the actual NC codes by using a
postprocessor .postprocessor .
The Aerospace Industries Association The Aerospace Industries Association
sponsored the work that led to the first part sponsored the work that led to the first part
programming language, developed in MIT in programming language, developed in MIT in
1955.1955.
This was called:This was called: Automatically Programmed Automatically Programmed
ToolsTools (APT). (APT).
APT is an English like simple programming APT is an English like simple programming
language which basically produce the language which basically produce the Cutter Cutter
LocationLocation (CL) data. (CL) data.
Using the cutter location data, the program can Using the cutter location data, the program can
generate the actual NC codes by using a generate the actual NC codes by using a
postprocessor .postprocessor .
136136
The output of any CAD package include the The output of any CAD package include the
geometric data of the part to be machined. geometric data of the part to be machined.
Therefore, many CAD/CAM package can Therefore, many CAD/CAM package can
produce cutter location (CL) data to be used for produce cutter location (CL) data to be used for
NC code generation.NC code generation.
There is still to be a process planning module There is still to be a process planning module
for a workable NC code generation. for a workable NC code generation.
Some of the CAD/CAM packages that have the Some of the CAD/CAM packages that have the
NC code generation capabilities are NC code generation capabilities are
Computervision, CATIA, CADAM, ProEngineer, Computervision, CATIA, CADAM, ProEngineer,
MechanicalDesktop (Auto Desk).MechanicalDesktop (Auto Desk).
CAD/CAM Based Part Programming:CAD/CAM Based Part Programming:
The output of any CAD package include the The output of any CAD package include the
geometric data of the part to be machined. geometric data of the part to be machined.
Therefore, many CAD/CAM package can Therefore, many CAD/CAM package can
produce cutter location (CL) data to be used for produce cutter location (CL) data to be used for
NC code generation.NC code generation.
There is still to be a process planning module There is still to be a process planning module
for a workable NC code generation. for a workable NC code generation.
Some of the CAD/CAM packages that have the Some of the CAD/CAM packages that have the
NC code generation capabilities are NC code generation capabilities are
Computervision, CATIA, CADAM, ProEngineer, Computervision, CATIA, CADAM, ProEngineer,
MechanicalDesktop (Auto Desk).MechanicalDesktop (Auto Desk).
CAD/CAM Based Part Programming:CAD/CAM Based Part Programming:
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