2. Computer Integrated
Manufacturing
• Computer Integrated Manufacturing,
known as CIM, is the phrase used to describe the
complete automation of a manufacturing plant,
with all processes functioning under computer
control and digital information tying them
together.
3. CIM
• It was promoted by machine tool manufacturers in
the 1980's and the Society for Manufacturing
Engineers (CASA/SME). Quite often it was
mistaken for the concept of a "lights out" factory. It
includes
• CAD/CAM, computer-aided design/computer-aided
manufacturing,
• CAPP, computer-aided process planning,
• CNC, computer numerical control machine tools,
DNC, direct numerical control machine tools,
4. • The heart of computer integrated manufacturing is
CAD/CAM. Computer-aided design (CAD) and
computer-aided manufacturing (CAM) systems are
essential to reducing cycle times in the organization.
• CAD/CAM is a high technology integrating tool
between design and manufacturing.
• CAD techniques make use of group technology to
create similar geometries for quick retrieval.
Electronic files replace drawing rooms.
CAD/CAM
5. • CAD/CAM integrated systems provide
design/drafting, planning and scheduling, and
fabrication capabilities. CAD provides the
electronic part images, and CAM provides the
facility for toolpath cutters to take on the raw
piece.
CAD/CAM
6. • The computer graphics that CAD provides allows
designers to create electronic images which can be
portrayed in two dimensions, or as a three
dimensional solid component or assembly which can
be rotated as it is viewed.
• Advanced software programs can analyze and test
designs before a prototype is made. Finite element
analysis programs allow engineers to predict stress
points on a part, and the effects of loading.
CAD/CAM
7. • Once a part has been designed, the graphics can be
used to program the tool path to machine the part.
When integrated with an NC postprocessor, the NC
program that can be used in a CNC machine is
produced.
• The design graphics can also be used to design tools
and fixtures, and for inspections by coordinate
measuring machines. The more downstream use
that is made of CAD, the more time that is saved in
the overall process.
CAD/CAM
10. A Definition:Numerical Control
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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12. Types of Numerical Control
• Conventional Numerical Control (NC)
• Direct Numerical Control (DNC)
• Computer Numerical Control (CNC)
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13. 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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14. 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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15. 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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17. Advantages
o Reduces time for
delivery of part
Reduces scrap rate of
material
o Reduces tooling
costs
o Reduces layout time
o Increases machine
and tool life
o Reduces storage
problems
o Less setup time
o Reduces actual
machining time
Allows rapid design
changes in part Less
jigs and fixtures are
needed
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21. 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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22. Preparatory Functions (G Codes)
G-codes
ß Tool motion
ß Rapid traverse G00
ß Positioning command
ß Moves the tool at a rapid feed rate to a specific XYZ
coordinate
ß Takes the shortest route to reach the specified point
ß Format
ß G00 Xx Yy Zz
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23. G-codes
Linear Interpolation
ß Moves the tool from its current position to a
specific XYZ coordinate at a specified feed
rate
ß Format
ß G01 Xx Yy Zz ff
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25. G-codes
Circular Interpolations
ß Moves a tool around a circular arc to a
specific XYZ coordinate
ß Requires 5 pieces of information
ß Plane selection
ß Arc start point
ß Rotation direction
ß Arc end point
ß Arc center or arc radius
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27. G-codes
How You Tell Directions
ß 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
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28. G-codes
Still Going in Circles
ß basic methods
ß Radius method
ß (G02,G03) Xx Yy Rr Ff (on the XY plane)
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29. G-codes
Radius Method
ß Requires two entry parameters in the
command the XYZ end point of the arc and
the radius R
ß G02/G03 Xx Yy Zz Rr
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