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Dr. Sotiris Omirou

Advanced CAD/CAM Systems

MDME502

CADProgram

CAMProgram

CNCMachineDrawing CNC File

Computer Aided Design• Geometry of part is created

Computer Aided Manufacturing• Program the part with G/M-codes

Computer Numerical Control• Produce the part

•Milling

•Lathe

•etc.

Structure of a CAD/CAM system

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THE MAIN PARTS OF A CNC MILLING MACHINE

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WORK HOLDING (1)

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WORK HOLDING (2)

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WORK HOLDING (3)

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CUTTING TOOLS: 1. End Mills

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CUTTING TOOLS: 2. Drills

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CUTTING TOOLS: 3. Reamers

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CUTTING TOOLS: 4. Mill shells

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REPRESENTATIVE PARTS

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Axes of Motion

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X Axis

Y Axis

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Z Axis

Directions of Linear Axes

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Directions of Rotary Axes

Y

X

YZ

ZERO REFERENCE POINT

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Y

X

YZ

ZERO REFERENCE POINT

Y

X

YZ

ZERO REFERENCE POINT

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Y

X

YZ

ZERO REFERENCE POINT

Y

X

YZ

ZERO REFERENCE POINT

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Y

X

YZ

ZERO REFERENCE POINT

TYPES OF COORDINATES

ABSOLUTE COORDINATES

INCREMENTALCOORDINATES

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When Working From Program Zero, You Are Programming In The

ABSOLUTE COORDINATES.

G90 Specifies The Absolute Mode.

ABSOLUTE COORDINATES

G91 Specifies The Incremental Mode

INCREMENTAL COORDINATES

In The Incremental Coordinates, Movements Are

Given From The Tool's LAST POSITION.

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ABSOLUTE / INCREMENTAL EXAMPLE

G90 G01 X90 Y80

G91 G01 X60 Y35

DEFINITION OF ZERO POINT

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The CNC Program

The CNC Program

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Codification of Letters in CNC Program

N Sequence Number

G Preparatory Function

X X Axis Coordinate

Y Y Axis Coordinate

Z Z Axis Coordinate

Codification of Letters in CNC Program

A/B/C Rotary Axes

R Radius

I/J/K Circle Center Coordinates

S Spindle Speed

F Feedrate

T Tool

M Miscellaneous Functions

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FUNCTIONS OF MOST COMMON G and M CODES

G CODE Function M CODE Function

G00 rapid linear motion M03 spindle on (CW)

G01 linear motion at preset feedrate F M08 coolant on

G02 circular feed motion - CW M09 coolant off

G03 circular feed motion – CCW M30 end program

G40 cutter compensation off

G41 cutter compensation left

G42 cutter compensation right

G70 units in inches

G71 units in mm

G90 absolute values

G91 incremental values

A SAMPLE CNC PROGRAM

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Milling Machine Animation

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