IE 447 COMPUTER INTEGRATED MANUFACTURING

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IE 447 COMPUTER INTEGRATED MANUFACTURING

• CHAPTER 3
• NUMERICAL CONTROL

Prepared by Hamed
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(No Transcript)
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A Definition
Numerical Control is a system in which actions
are controlled by the direct insertion of
numerical data at some point. The system must
automatically interpret at least some portion of
the data
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NUMERICAL DATA (NC CODE)
NUMERICAL CONTROLLER
MANUFACTURING OPERATOR
Drive Control
PROCESSED PART
MACHINE UNIT
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Types of Numerical Control

• Conventional Numerical Control (NC)
• Direct Numerical Control (DNC)
• Computer Numerical Control (CNC)

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Conventional Numerical Control (NC)
Data is sent to the machine tool by means of
punch cards or tapes. The reader at the machine
performs no calculations or interpolations.
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Direct Numeric Control (DNC)
Is a method where a single computer controls
many numerical control machine tools. These
machine tools may or may not be of a similar
nature
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Computer Numerical Control (CNC)
The idea of computer numerical control is to
position a computer right at the machine tool.
Most, if not all machine tools that are
numericaly controlled are CNC machine tools.
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Computer Numerical Control (CNC)
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Advantages

• Reduces time for delivery of part Reduces scrap
  rate of material
• Reduces tooling costs
• Reduces layout time
• Increases machine and tool life

• Reduces storage problems
• Less setup time
• Reduces actual machining time Allows rapid design
  changes in part Less jigs and fixtures are needed

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NC Programming Fundamentals
or how to put the GO in your G-codes
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NC Part Programming

• Linear tool motion (Milling) relative to the part

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Example A Milling Operation
SPINDLE STOP !
NC CODE (Word Address Format) N50 G00 X15 Y12.5
Z0 N55 M03 N60 G01 Z-2.5 F500 M08 N65 G01 X50 N70
G01 Y45 N75 G01 X15 N80 G01 Y12.5 N85 G00 Z0
M09 N90 G79 M04
SPINDLE STARTED !
Z
Y
X
(0,0,0)
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Basics of NC Part Programming

• it is always assumed that the tool moves relative
  to the work piece no matter what the real
  situation is.
• The position of the tool is described by using a
  Cartesian coordinate system.
• If (0,0,0) position can be described by the
  operator, then it is called floating zero.

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Preparatory Functions (G Codes)

• Tool motion
• Rapid traverse G00
• Positioning command
• Moves the tool at a rapid feed rate to a specific
  XYZ coordinate
• Takes the shortest route to reach the specified
  point
• Format
• G00 Xx Yy Zz

G-codes
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Linear Interpolation

• Moves the tool from its current position to a
  specific XYZ coordinate at a specified feed rate
• Format
• G01 Xx Yy Zz ff

G-codes
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Linear Interpolation
G-codes
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Circular Interpolations

• Moves a tool around a circular arc to a specific
  XYZ coordinate
• Requires 5 pieces of information
• Plane selection
• Arc start point
• Rotation direction
• Arc end point
• Arc center or arc radius

G-codes
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Circular Interpolations

• G02 circular interpolation clockwise around an
  arc G03 circular interpolation counter clockwise
  around an arc

G-codes
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How You Tell Directions

• The direction for G02 can be determined by
  rotating from the positive axes towards the
  negative axes. The direction for a G03 is exactly
  opposite

G-codes
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Still Going in Circles

• basic methods
• Radius method
• (G02,G03) Xx Yy Rr Ff (on the XY plane)

G-codes
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Radius Method

• Requires two entry parameters in the command the
  XYZ end point of the arc and the radius R
• G02/G03 Xx Yy Zz Rr

G-codes
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G90 M3 S2000 G90 -absolute coordinate M3 -
spindle ON S - RPM G0 X0 Y0 Z10 G0- rapid
movement X10 Y5 Z2 G1 Z-2 F100 G1- linear
movement F- feed X80 F200 X10 Y40 Y5 x80
Y40 x45 y45 x10 y40 x80 x80 y5 g0 z10 x0y0 M30
Spindle off
X45 y45
X80 y40
X5 y40
X80 y10
X5 y10
G-codes
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G-codes
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Quiz
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Homework 1 - Due date March 10th
Z-2
Tool Diameter 0.5 mm
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CNC Pro-Light 1000 Machine
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G-codes
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Spindle On/Off
Vice Open/Close
E-stop
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1- Machine Home
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2- Reference Point
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3. Set position
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4- Run