CAD

1. Computer Aided Design and
Manufacturing
Chapter # 01
Fundamentals of CAD
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2. Marks Distribution
Class Attendance/Class Behavior/Evaluation 5%
Assignments/Projects/Presentations 10%
Quizzes/Projects/Presentations 10%
Mid Term Exam 25%
End Semester Exam 50%
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3. About the course
 Computer Aided Design and Computer Aided Manufacturing
(CAD/CAM) Emerged as a course in 1950s.
 It has now evolved into several areas like Geometric modeling,
Machine vision and Flexible Manufacturing System.
 Core course of Mechanical engineering.
 Application in several industries.
 Automobile engineering, Marine engineering, Aerospace
engineering.
 CAD helps to improve product quality, increase productivity,
flexibility and to reduce inventory costs.
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4. Contents
 Part I ( Fundamentals of Design, Computers and Controllers)
 Chapter # 1
 Chapter # 2
 Chapter # 3
 Part II (Hardware and Software Components)
 Chapter # 4
 Chapter # 5
 Chapter # 6
 Part III (Design Aspects of Industrial Components)
 Chapter # 7
 Chapter # 8
 Chapter # 9
 Chapter # 10
 Chapter # 11
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5. Introduction
 CAD can be defined as the use of computer systems to assist
in the creation, modification, analysis or optimization of a
design.
 Computer assistance while a designer converts his or her
ideas and knowledge into a mathematical and graphical
model represented in a computer.
 CAD/CAM is focused on reducing time for designing the
product and all other activities which are accomplished once
for each product and time associated with planning and
setting up for each batch ofproduction.
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6. Introduction
 Latest techniques of geometric modeling and manufacturing
like rapid prototyping (RP) have bridged the gap between
product conceptualization and product realization.
 Modern CAD systems are based on Interactive Computer
Graphics (ICG).
 ICG denotes a user-oriented system in which the computer is
employed to create, transform and display data in the form of
pictures or symbols.
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7. Introduction
 The ICG system is a combination of Hardware and Software.
 Hardware Includes
 CPU
 Printers
 Drafting equipment.
 The software consists of the computer programs needed to
implement graphics processing on the system.
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8. Design Process
 Design
 Design is an act of devising an original solution to a problem by a
combination of principles, resources and products in design.
 It is the pattern of activities that is followed by designer in arriving at
the solution of a technological problem.
 It is an iterative process and the design is improved more and more as
we gather more information.
 Models of the design process
 The design progress is a step by step manner from statement of need
through identification of problem, a search for solutions and
development of chosen solution to trial production and use.
 There are four models of design processes that includes Shigley, Phal
and Beitz, Ohsuga and Earle.
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9. Design Process 9

10. Models of the Design Process
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11. Shigley Model 11

12. Shigley Model
 Recognition of need:
 Realization that a problem exists for which some feasible solution exists.
 Definition of problem:
 Through specification of the item to be designed.
 Synthesis:
 Various ideas are developed through the research of similar products or design in
use.
 Analysis and Optimization:
 Analysis to determine their suitability for the specified design constraints. If the
design fails then again steps will be taken to improve and optimize the design.
 Evaluation:
 Fabrication and testing of prototype to evaluate performance quality and
reliability.
 Presentation:
 Presentation of the design
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13. Ohsuga Model 13

14. Earle Model 14

15. Earle Model
 Problem Identification
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16. Preliminary Ideas 16

17. Design refinement 17

18. Analysis 18

19. Decision 19

20. Implementation 20

21. BENEFITS OF CAD
 Productivity Improvement in Design
 Depends on Complexity of drawing
 Degree of repetitiveness of features in the designed parts
 Degree of symmetry in the parts
 Extensive use of library of user defined shapes and commonly used entities
 Shorter Lead Times
 Flexibility in Design
 Design Analysis
 Fewer Design Error
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22. BENEFITS OF CAD
 Standardization of Design, Drafting and Documentation
 Drawings are more understandable
 Improved Procedures of Engineering Changes
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23. REASONS FOR IMPLEMENTING
CAD
 To increase the productivity of the designer
 To improve the Quality of Design
 To improve Documentation
 To create a Database for manufacturing
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24. APPLICATION OF COMPUTERS TO
DESIGN
 Modeling of the Design
 Engineering design and analysis

 Evaluation of Prototype through Simulation and Testing
 Drafting and Design Documentation
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25. Difference between CAD and CAM
CAD CAM
CAD is the implementation of digital
computers in engineering design and
production.
CAM is the implementation of
computers in transforming engineering
designs into end products.
Design conceptualization and analysis.
Control and coordination of the
necessary physical processes,
equipment, materials, and labour.
Computer + Designing Software = CAD Manufacturing Tool + Computer = CAM
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26. Self Study
 Pahl and Beitz Model
 Article: 1.4.2
 Book Page number : 06
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27. THANK YOU
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