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CNC CNC TECHNOLOGYTECHNOLOGY

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INTRODUCTION TO INTRODUCTION TO CNCCNC

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CC NN CC

ComputerComputer NumericalNumerical ControlControl

DEFINITIONDEFINITION

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CNC TECHNOLOGYCNC TECHNOLOGY• The CNC stands for Computer Numerical ControlThe CNC stands for Computer Numerical Control• Instructions are stored as a program in micro-computer Instructions are stored as a program in micro-computer

attached to the machine.attached to the machine.• Refers to a computer controller that controls the Refers to a computer controller that controls the

movement of every axis of the machinemovement of every axis of the machine• Using G and M codes instructionsUsing G and M codes instructions• Drives the spindle or machine tool into a raw material to Drives the spindle or machine tool into a raw material to

fabricate or to remove the unwanted material from work fabricate or to remove the unwanted material from work piece more accurately without human intervention.piece more accurately without human intervention.

• The computer will also handle much of the controllogic of The computer will also handle much of the controllogic of the machine, making it more adaptable than earlier hard-the machine, making it more adaptable than earlier hard-wired controllers.wired controllers.

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HISTORYHISTORY

1949US Air Force asks MIT to develop a "numerically controlled" machine that are programmable milling machine.

1952Prototype NC machine demonstrated (punched tape input)

The birth of NC is generally credited to John T. Parsons, a machinist and salesman at his father's machining company, Parsons Corp.

1947 Using punched cards he was able to control the position of a machine in an attempt to machine helicopter blade.

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1959Machining centers and turning centers that could perform multiple machining processes was developed.

Modern NC machine has a computer on board, Computer Numerical Control (CNC). They can run unattended at over 20,000 rpm (spindler speed) with a feed rate of over 600 ipm and an accuracy of .0001..

1990-DNC: external computer “drip feeds” control programmer to machine tool controller

1980-CNC machines (computer used to link directly to controller)

HISTORYHISTORY

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NCNC

• A control system which primarily processes numeric A control system which primarily processes numeric input.input.

• Limited programming capability at the machine tool.Limited programming capability at the machine tool.

• Limited logic beyond direct input.Limited logic beyond direct input.

• These types of systems are referred to as “hardwire These types of systems are referred to as “hardwire controls” and were popular from the 1950’s to controls” and were popular from the 1950’s to 1970’s.1970’s.

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NCNC

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CNCCNC

• A numerical control system in which the data A numerical control system in which the data handling, control sequences, and response to handling, control sequences, and response to input is determined by an on-board computer input is determined by an on-board computer system at the machine tool. system at the machine tool.

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CNCCNC

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To manufacture complex curved geometries in 2D or 3D was extremely expensive by mechanical means (which usually would require complex jigs to control the cutter motions)

CNC APPLICATIONSCNC APPLICATIONS

Machining components with repeatable accuracy

Unmanned machining operations

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CNC APPLICATIONSCNC APPLICATIONS

• 2.5D / 3D 2.5D / 3D

• Turning : Lathes, Turning Centre Turning : Lathes, Turning Centre

• Milling : Machining Centres Milling : Machining Centres

Machining

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• 2D2D

• 3D3D

• Plasma & Laser CuttingPlasma & Laser Cutting

• Blanking, Nibbling & PunchingBlanking, Nibbling & Punching

• Rapid PrototypingRapid Prototyping

Forming

CNC APPLICATIONSCNC APPLICATIONS

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TYPES OFTYPES OF CNC MACHINES CNC MACHINES

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CNC TCNC Turningurning

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CNC TCNC Turning with Slant Bedurning with Slant Bed

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CNC MCNC Millingilling

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CNC CNC Machining CenterMachining CenterHorizontal AxisHorizontal Axis

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CNC CNC Coordinate MeasuringCoordinate Measuring

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CNC CNC EDM Wire CutEDM Wire Cut

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CNC LCNC Laseraser C Cuttingutting

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CNC PCNC Plasmalasma C Cuttingutting

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CNC PCNC Pressress

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CNC RCNC Rapidapid P Prototypingrototyping

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INDUSTRIES MOSTINDUSTRIES MOST AFFECTED AFFECTED &&

SAMPLE PRODUCTSSAMPLE PRODUCTS OF OF

CNC MANUFACTURINGCNC MANUFACTURING

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AUTOMOTIVE INDUSTRYAUTOMOTIVE INDUSTRYEngine BlockEngine Block

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AUTOMOTIVE INDUSTRYAUTOMOTIVE INDUSTRYDifferent ProductsDifferent Products

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AEROSPACE INDUSTRYAEROSPACE INDUSTRYAircraft TurbineAircraft Turbine

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MOLD MAKINGMOLD MAKINGBody PartsBody Parts

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ELECTRONIC INDUSTRYELECTRONIC INDUSTRYTelecomunicationTelecomunication

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RAPID PROTOTYPING RAPID PROTOTYPING PRODUCTSPRODUCTS