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Dr. HABEEB HATTAB HABEEB Office: BN-Block, Level-3, Room-088 Email: [email protected] Ext. No.: 7292. U niversity TENAGA National College Of Engineering Mechanical Department. Lecture Note. Computer Aided Manufacturing. CAM. - PowerPoint PPT Presentation
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University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Dr. HABEEB HATTAB HABEEBDr. HABEEB HATTAB HABEEB
Office: BN-Block, Level-3, Office: BN-Block, Level-3, Room-088Room-088
Email: Email: [email protected]. No.: 7292Ext. No.: 7292
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
UUniversity TENAGA Nationalniversity TENAGA National
College Of EngineeringCollege Of EngineeringMechanical DepartmentMechanical Department
Lecture NoteLecture Note
University TENAGA Nasional Lecturer: Habeeb Al-Ani
CAMCAM
Computer Aided ManufacturingComputer Aided Manufacturing
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Overview
• Computer Aided Manufacturing Defined• Brainstorming Exercise• CAM activities• How It Works• Summary• Conclusion
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
• What is Computer Aided Manufacturing?
– It is “control of the manufacturing process by
computers” involving the integration of CAD
engineering data and the computerized
equipment which manufactures the product.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
• Other definitions:– “Computer aided manufacturing concerns the use
of algorithms for planning and controlling fabrication processes.”
– Computer aided manufacturing is “the use of computers for managing manufacturing processes.”
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Computer Aided Manufacturing
• Using technology to produce• Leveraging capital investments• Increasing productivity through automation• Decreasing lead time through programming
and controlled machinery
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Brainstorming Exercise
• How can CAM benefit your company?– Integrate design and manufacturing– Make mass customization possible– Reduce costs– Leverage computing power– Automate manufacturing processes
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Brainstorming Exercise
• Identify benefits and costs of CAM:– Direct Benefits– Indirect Benefits– Tangible Costs– Intangible Costs
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Brainstorming Exercise
• What processes in your company could be more efficient through CAM?
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
CAM activities
• Essentially the collection of computer technologies used in manufacturing– Computer Numerical Control (CNC)– Direct Numerical Control (DNC)– Flexible Manufacturing System (FMS)– Robots– Automated material Handling Systems
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
• Computer Numerically Controlled (CNC)– Machine that is controlled by computer– Utilizes monitor and keyboard for operator
interaction– Facilitates greater control over quality– Allows machine to monitor the maintenance of
its parts
CAM activities
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
• Direct Numerical Control (DNC)– Each machine contains own microprocessor– Entire bank of machines controlled by a single
central computer– If used with automated material handling,
considered to be a flexible manufacturing system
CAM activities
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
• Direct Numerical Control (DNC)
CAM activities
• Direct Numerical Control (DNC)
CAM activities
• Flexible Manufacturing System (FMS)– Numerous computer-controlled machines fed by
automated material handling system– Allows for broad and deep product mix– Minimal setup times enable small lot sizes
CAM activities
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
• Robots– Mechanical manipulators that can be accessed
with programming method– Consistent, repetitive-motion tolerant– Ideal for tasks that are hazardous to humans
CAM activities
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
• Automated Materials Handling System– System where raw materials are automatically
fed into machines– Examples:
• Conveyor belts• Automated Guided Vehicles (AGV)• Automated Storage and Retrieval Systems (ASRS)
CAM activities
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
How It Works
1. Product is conceived by engineer2. Product is designed using CAD software3. CAD data is transferred to manufacturing
machine’s memory4. Machine uses the CAD data to produce the
product, with little human intervention
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
How It Works
• Old System (without CAM)– Product is designed with CAD software
• Each production machine is programmed individually
OR – if not automated :• Employees are trained on proper production of the
product
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
How It Works
• New System (using CAM)– Product is designed with CAD software
• Product specifications are sent over the plant network to each machine
• Machines have ‘intelligence’ to produce the products without human intervention
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
– CAM solution:• Enables faster turnaround of new products• Reduces waste by using raw materials more
efficiently• Generates costs based on design specifications
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Summary
• Here’s what we’ve looked at so far….– Definition– Brainstormed– CAM activities– How It Works– CAM solution
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Conclusion
• CAM enables companies to leverage capital investment
• CAM allows for cost savings that can be passed on to the final consumer
• CAM utilizes human resources more efficiently to minimize labor costs
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
RememberRemember && rememberremember XX 1000 1000
If you want to be part of a profession dedicated to quality
and continuous improvement, consider CAM as your career of choice…
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
CAM Systems & CNC CAM Systems & CNC MachineMachine
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
History
• 1955 - John Parsons and US Air Force define a need to develop a machine tool capable of machining complex and close tolerance aircraft parts with the same quality time after time. MIT is the subcontractor and builds the machine for the project.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
History: Continued
• 1959 - MIT announces Automatic Programmed Tools (APT) programming language
• 1960 - Direct Numerical Control (DNC). This eliminates paper tape punch programs and allows programmers to send files directly to machine tools
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
History: Continued
• 1968 - Kearney & Trecker machine tool builders market first machining center
• 1970’s - CNC machine tools & Distributed Numerical Control
• 1980’s - Graphics based CAM systems introduced. Unix and PC based systems available
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
History: Continued
• 1990’s - Price drop in CNC technology• 1997 - PC- Windows/NT based “Open
Modular Architecture Control (OMAC)” systems introduced to replace “firmware” controllers.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Control Systems
• Open-Loop Control– Stepper motor system– Current pulses sent from control unit to motor– Each pulse results in a finite amount of revolution
of the motor001” is possible
Control Systems
• Open-Loop Limitations– Control unit “assumes” desired position is
achieved– No positioning compensation– Typically, a lower torque motor
• Open-Loop Advantages– Less complex, Less costly, and lower maintenance
costs
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Control Systems
• Closed-Loop Control– Variable DC motors - Servos– Positioning sensors -Resolvers
• Feedback to control unit • Position information compared to target location• Location errors corrected
Control Systems
• Closed-Loop Advantages– DC motors have the ability to reverse
instantly to adjust for position error– Error compensation allows for greater
positional accuracy (.0001”)– DC motors have higher torque ranges..
stepper motors
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Control Systems
• Closed-loop limitations– Cost
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Three Basic Categories of Motion Systems
• Point to Point - No contouring capability • Straight cut control - one axis motion at a
time is controlled for machining• Contouring - multiple axis’s controlled
simultaneously
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Three Basic Categories of Motion Systems
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
CNC - NC Machine Tools
• Computer Numerical Control (CNC) - A numerical
control system in which the data handling, control
sequences, and response to input is determined by
an on-board computer system at the machine tool.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
CNC
• Advantages– Increased Program storage capability at the machine tool
– Program editing at the machine tool
– Control systems upgrades possible
– Option -resident CAM system at machine tool
– Tool path verification
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Machining Centers
– Machine motion is programmable
– Servo motors drive feed mechanisms for tool
axis’s
– Positioning feedback is provided by resolvers to
the control system
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
NC
• Numerical Control (NC) - A control system which primarily processes numeric input. Limited programming capability at the machine tool. Limited logic beyond direct input. These types of systems are referred to as “hardwire controls” and were popular from the 1950’s to 1970’s.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Machining Centers
• A machining center can be defined as a machine tool capable of:– Multiple operation and processes in a
single set-up utilizing multiple axis– Typically has an automatic mechanism to
change tools
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Machining Centers
• Example - A turning center capable of OD turning, external treading, cross-hole drilling, engraving, and milling. All in machining is accomplished in one “set-up.” Machine may have multiple spindles.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Programming Methods-APT
– Developed as a joint effort between the aerospace industry, MIT, and the US Airforce
– Still used today and accounts for about 5 -10% of all programming in the defense and aerospace industries
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Machining Centers
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Programming Methods
• Automatically Programmed Tools (APT)– A text based system in which a programmer
defines a series of lines, arcs, and points which define the overall part geometry locations. These features are then used to generate a cutter location (CL) file.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Programming Methods-APT
– Requires excellent 3D visualization skills
– Capable of generating machine code for complicated part programs
• 5 axis machine tools
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Programming Methods-APT
• Part definition– P1=Point/12,20,0– C1=Circle/Center,P1,Radius,3– LN1=Line/C1. ATANGL,90
• Cutter Commands– TLRT,GORT/LN1.TANTO,C1– GOFWD/C1,TANTO,L5
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Programming Methods-CAM
• Computer Aided Machining (CAM) Systems– Graphic representation of the part– PC based– Integrated CAD/CAM functionality– “Some” built-in expertise
– Speed & feed data based on material and tool specifications
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Programming Methods-CAM
– Tool & material libraries– Tool path simulation– Tool path editing– Tool path optimization – Cut time calculations for cost estimating
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Programming Methods-CAM
– Import / export capabilities to other systems• Examples:
– Drawing Exchange Format (DXF)– Initial Graphics Exchange Standard (IGES)
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
The Process CAD to NC File
• Start with graphic representation of part– Direct input– Import from external system
• Example DXF / IGES
– 2D or 3D scan• Model
(At this point you have a graphics file of your geometry)
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
The Process CAD to NC File
• Define cutter path by selecting geometry– Contours– Pockets– Hole patterns– Surfaces– Volume to be removed
(At this point the system knows what you want to cut)
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
The Process CAD to NC File
• Define cut parameters– Tool information
• Type, Rpm, Feed
– Cut method• Example - Pocket mill zig-zag, spiral, inside-out• Rough and finish parameters
(At this point the system knows how you want to cut the part)
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
The Process CAD to NC File
• Execute cutter simulation– Visual representation of cutter motion
• Modify / delete cutter sequences
(At this point the system has a “generic” cutter location (CL) file of the cut paths)
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
The Process CAD to NC File
• Post Processing– CL file to machine specific NC code
• Filters CL information and formats it into NC code based on machine specific parameters– Work envelope– Limits - feed rates, tool changer, rpm’s, etc. – G & M function capabilities
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Output: NC Code
• Numerical Control (NC) Language– A series of commands which “direct” the cutter
motion and support systems of the machine tool.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Output: NC Code
• G-Codes (G00, G1, G02, G81)
• Coordinate data (X,Y,Z)
• Feed Function (F)
• Miscellaneous functions (M13)
• N - Program sequence number
• T - Tool call
• S - Spindle command
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Output: NC Code
• NC Program Example – N01G90 G80– N03 GOO T12 M06– N05 GOO X0 Y0 Z.1 F10 S2500 M13– N07 G1Z-.5– N09 G02 X-10. I0J0F20– N13 X0Y10– N17 X10Y0– N19 X0Y-10– N21 X-10Y0– N23 M2
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Example of CNC Programming
• What What Must Be Done To Drill A Hole On A CNC Vertical Milling Machine
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
Tool Home
1.) X & Y Rapid To Hole Position
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
2.) Z Axis Rapid Move
Just Above Hole
3.) Turn On Coolant
4.) Turn On Spindle
.100”
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
5.) Z Axis Feed Move to
Drill Hole
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
6.) Rapid Z Axis Move
Out Of Hole
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
9.) X&Y Axis Rapid
Move Home
7.) Turn Off Spindle
8.) Turn Off Coolant
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
Tool At Home
O0001N005 G54 G90 S600 M03N010 G00 X1.0 Y1.0N015 G43 H01 Z.1 M08N020 G01 Z-.75 F3.5
N030 G91 G28 X0 Y0 Z0N035 M30
N025 G00 Z.1 M09
Here’s The CNC Program!
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
Tool At Home
O0001O0001
Number Assigned to this program
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
Tool At Home
O0001N005 G54 G90 S600 M03N005 Sequence Number
G54 Fixture Offset
G90 Absolute Programming Mode
S600 Spindle Speed set to 600 RPM
M03 Spindle on in a Clockwise Direction
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
O0001N005 G54 G90 S600 M03N010 G00 X1.0 Y1.0
G00 Rapid Motion
X1.0 X Coordinate 1.0 in. from Zero
Y1.0 Y Coordinate 1.0 in. from Zero
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
O0001N005 G54 G90 S600 M03N010 G00 X1.0 Y1.0N015 G43 H01 Z.1 M08G43 Tool Length Compensation
H01 Specifies Tool length compensation
Z.1 Z Coordinate .1 in. from Zero
M08 Flood Coolant On
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
O0001N005 G54 G90 S600 M03N010 G00 X1.0 Y1.0N015 G43 H01 Z.1 M08N020 G01 Z-.75 F3.5
G01 Straight Line Cutting Motion
Z-.75 Z Coordinate -.75 in. from Zero
F3.5 Feed Rate set to 3.5 in./min.
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
O0001N005 G54 G90 S600 M03N010 G00 X1.0 Y1.0N015 G43 H01 Z.1 M08N020 G01 Z-.75 F3.5
G00 Rapid Motion
Z.1 Z Coordinate .1 in. from Zero
M09 Coolant Off
N025 G00 Z.1 M09
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
O0001N005 G54 G90 S600 M03N010 G00 X1.0 Y1.0N015 G43 H01 Z.1 M08N020 G01 Z-.75 F3.5
N030 G91 G28 X0 Y0 Z0G91 Incremental Programming Mode
G28 Zero Return Command
X0, Y0, Z0
X,Y,& Z Coordinates at Zero
N025 G00 Z.1 M09
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Top View
Front View
O0001N005 G54 G90 S600 M03N010 G00 X1.0 Y1.0N015 G43 H01 Z.1 M08N020 G01 Z-.75 F3.5
N035 M30N030 G91 G28 X0 Y0 Z0N025 G00 Z.1 M09
M30 End of Program
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Output: NC Code - Canned Cycles
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
CAD to NC Code
Geometry Direct input
Tool Path Generation What you want to cut How you want to cut
Tool Type Rpm’s – Feeds Method
Canned cycles Cut direction
Post Process
DXFIGES
ImportFile
CLFile
NC CodeN1 G80 G90N3 G0 T01 M06N5 G0 X0 Y0
OEMCustom
Language
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Advantages of CNC Machine Tools
• Ease of part duplication• Flexibility• Repeatability• Quality control through process control
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Advantages of CNC Machine Tools
• Accommodates simple to complex parts geometry
• Improved part aesthetics• Increased productivity• Technology costs are decreasing
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Advantages of CNC Machine Tools
• Reduced set-up time• Reduced lead times• Reduced inventory• Better machine utilization• Job advancement opportunities
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
Advantages of CNC Machine Tools
• CNC machine tools are more rigid than conventional machine tools– $$$- Climb milling requires about 10 - 15 % less horsepower
vs. conventional cutting, but requires a ridged machine tool with no backlash
– Increased Rpm’s and feeds
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI
University TENAGA Nasional Lecturer: Dr. HABEEB ALANI