DEPARTMENT OF MECHANICAL ENGINEERING
Subject Name: Computer Integrated Manufacturing systems
Subject Code : ME6703
UNIT I INTRODUCTION
Brief introduction to CAD and CAM – Manufacturing Planning,
Manufacturing control- Introduction to CAD/CAM – Concurrent
Engineering-CIM concepts – Computerized elements of CIM
system –Types of production - Manufacturing models and Metrics
– Mathematical models of Production Performance – Simple
problems – Manufacturing Control – Simple Problems – Basic
Elements of an Automated system – Levels of Automation – Lean
Production and Just-In-Time Production.
2 Marks
Brief introduction to CAD and CAM
1. What are the advantages to be gained by the adoption of CAD?
(AU Dec 13)
Reduced design timescales.
Reuse of designs.
Drawing errors can be corrected easily.
Drawings can be sent/received via email in seconds
2. What are the features of CAD package? [May/June 2012)
The features of CAD package are edit 2D, 3D, Wireframe, Surface or
solid modeling. 3D solids can be produced using solid primitives or from 2D
using commands like extrude, revolve etc. Surface area, Mass, Volume,
Centroid and MI can be calculated using MASSPROP command.
3. List any two reasons for using a CAD system.(AU Nov/Dec ‘11)
To increase the productivity of the designer.
1
, To improve the quality of the design
To improve design documentation
To create a manufacturing data base
4. What are the components of a CAD system? (AU Nov/Dec ‘11)
Geometric modeling
Engineering analysis
Design Review and evaluation
Automated Drafting
5. Write the various methods for representing the solids in CAD.
[April/May 2015]
There are three different forms in which a solid model can be represented in
CAD:
• Wireframe Model
• Surface Model
• Solid Model
6. Mention the reasons for implementing CAD.[April/May 2015]
The reason for implementing CAD
1. To increase the productivity of the designer.
2. To improve the quality of design.
3. To improve communications through documentation.
4. To create a database for manufacturing
7. What are the steps design processes?
Design Process:
The process of designing something is characterized as an interactive
2
,procedure, which consists of six identifiable steps or phases:
1. Recognition of need
2. Definition of problem
3. Synthesis
4. Analysis and optimization
5. Evaluation
6. Presentation
8. Define geometric modeling?
Modeling is the complete representation of an object that includes both
its graphical and non-graphical information. Modeling of an engineering
object consists of geometry, topology and auxiliary information. Geometry
includes points, lines, circles, planes, cylinders and other surfaces. It defines
the basic shapes characteristics.
9. What are the types of modeling system?
3D modeling in CAD can be divided into three classes as follows.
i. Wire frame modeling.
ii. Surface modeling (Polyhedral & Sculptured).
iii. Solid modeling.
10. Define wire frame modeling?
Wire frame modeling is the first, simplest and the strongest forward
modeling technique. This was developed in 1960 for 2D and 1970 for 3D.In
this geometry is defined as a series of lines and curves representing the
edges of sometimes sections through the object. It is so called wire frame as
the drawing looks like a wire model when viewed on a computer screen or
hard copy.
11. What are the advantages of wire frame modeling?
i. Needs very loss memory in computer.
ii. Models can be quickly drawn.
iii. It is the basics for surface models.
3
, iv. CPU time required for retrieval, edit etc. is very less.
v. Simplest to handle and easy to draw.
12. What are the disadvantages of wire frame modeling?
1. Not suitable for large and complex objects.
2. Mass, volume and M.I etc. cannot be calculated.
3. Sometimes wire frame models are ambiguous.
13. Define surface modeling?
In surface modeling defined as a two-dimensional collection of points
(flat surface), a three-dimensional collection of points whose cross section is
a curve (curved surface), or the boundary of any three-dimensional solid. In
general, a surface is a continuous boundary dividing a three-dimensional
space into two regions. For example, the surface of a sphere separates the
interior from the exterior
14. What are the advantages of surface modeling? AU MAY-12
o It is more complete and less ambiguous then wire frame model and
more suitable for engineering applications.
Used for components of smoothly varying sections, designing
components in ship building, air craft, automobile body works shoe
leather cutting, jewels, pottery, glassmaking and garment industrials.
Surface models can be used for volume, mass, property calculations,
FEM, NC path generation, cross sectioning and interference detections.
15. What are the types of solid modeling?
i. Primitive instancing
ii. SOE
iii. Cell de composition
iv. CSG
v. B-rep
vi. Sweeping
a. Translation sweep
b. Rotation sweep
4
Subject Name: Computer Integrated Manufacturing systems
Subject Code : ME6703
UNIT I INTRODUCTION
Brief introduction to CAD and CAM – Manufacturing Planning,
Manufacturing control- Introduction to CAD/CAM – Concurrent
Engineering-CIM concepts – Computerized elements of CIM
system –Types of production - Manufacturing models and Metrics
– Mathematical models of Production Performance – Simple
problems – Manufacturing Control – Simple Problems – Basic
Elements of an Automated system – Levels of Automation – Lean
Production and Just-In-Time Production.
2 Marks
Brief introduction to CAD and CAM
1. What are the advantages to be gained by the adoption of CAD?
(AU Dec 13)
Reduced design timescales.
Reuse of designs.
Drawing errors can be corrected easily.
Drawings can be sent/received via email in seconds
2. What are the features of CAD package? [May/June 2012)
The features of CAD package are edit 2D, 3D, Wireframe, Surface or
solid modeling. 3D solids can be produced using solid primitives or from 2D
using commands like extrude, revolve etc. Surface area, Mass, Volume,
Centroid and MI can be calculated using MASSPROP command.
3. List any two reasons for using a CAD system.(AU Nov/Dec ‘11)
To increase the productivity of the designer.
1
, To improve the quality of the design
To improve design documentation
To create a manufacturing data base
4. What are the components of a CAD system? (AU Nov/Dec ‘11)
Geometric modeling
Engineering analysis
Design Review and evaluation
Automated Drafting
5. Write the various methods for representing the solids in CAD.
[April/May 2015]
There are three different forms in which a solid model can be represented in
CAD:
• Wireframe Model
• Surface Model
• Solid Model
6. Mention the reasons for implementing CAD.[April/May 2015]
The reason for implementing CAD
1. To increase the productivity of the designer.
2. To improve the quality of design.
3. To improve communications through documentation.
4. To create a database for manufacturing
7. What are the steps design processes?
Design Process:
The process of designing something is characterized as an interactive
2
,procedure, which consists of six identifiable steps or phases:
1. Recognition of need
2. Definition of problem
3. Synthesis
4. Analysis and optimization
5. Evaluation
6. Presentation
8. Define geometric modeling?
Modeling is the complete representation of an object that includes both
its graphical and non-graphical information. Modeling of an engineering
object consists of geometry, topology and auxiliary information. Geometry
includes points, lines, circles, planes, cylinders and other surfaces. It defines
the basic shapes characteristics.
9. What are the types of modeling system?
3D modeling in CAD can be divided into three classes as follows.
i. Wire frame modeling.
ii. Surface modeling (Polyhedral & Sculptured).
iii. Solid modeling.
10. Define wire frame modeling?
Wire frame modeling is the first, simplest and the strongest forward
modeling technique. This was developed in 1960 for 2D and 1970 for 3D.In
this geometry is defined as a series of lines and curves representing the
edges of sometimes sections through the object. It is so called wire frame as
the drawing looks like a wire model when viewed on a computer screen or
hard copy.
11. What are the advantages of wire frame modeling?
i. Needs very loss memory in computer.
ii. Models can be quickly drawn.
iii. It is the basics for surface models.
3
, iv. CPU time required for retrieval, edit etc. is very less.
v. Simplest to handle and easy to draw.
12. What are the disadvantages of wire frame modeling?
1. Not suitable for large and complex objects.
2. Mass, volume and M.I etc. cannot be calculated.
3. Sometimes wire frame models are ambiguous.
13. Define surface modeling?
In surface modeling defined as a two-dimensional collection of points
(flat surface), a three-dimensional collection of points whose cross section is
a curve (curved surface), or the boundary of any three-dimensional solid. In
general, a surface is a continuous boundary dividing a three-dimensional
space into two regions. For example, the surface of a sphere separates the
interior from the exterior
14. What are the advantages of surface modeling? AU MAY-12
o It is more complete and less ambiguous then wire frame model and
more suitable for engineering applications.
Used for components of smoothly varying sections, designing
components in ship building, air craft, automobile body works shoe
leather cutting, jewels, pottery, glassmaking and garment industrials.
Surface models can be used for volume, mass, property calculations,
FEM, NC path generation, cross sectioning and interference detections.
15. What are the types of solid modeling?
i. Primitive instancing
ii. SOE
iii. Cell de composition
iv. CSG
v. B-rep
vi. Sweeping
a. Translation sweep
b. Rotation sweep
4
