Engineering Design and CAD

Engineering Design and CAD
Dr Sanjay Sharma PhD
Automatic control and systems engineering department, University of Sheffield

Research Engineer Intelligent system and control research group, Queens University of Belfast Lecturer School of Engineering, University of Plymouth
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Engineering Design and CAD

Module description:
Module Code : DSGN131 (T1 and T2)
Module Name Class Duration Rooms : Engineering design and CAD : 2 hrs : SMB104
Credits Assessment
: 20 : Coursework 1 (40%) + Coursework 2 (60%)
Minimum pass mark for the module : 40%
Engineering Design
What it is?
What is Design? In an engineering context, the word "Design" refers to problem solving, i.e., the application of engineering science and technology to solve real-world problems. Design is at the heart of mechanical, civil, electrical, chemical, and computer engineering. Much of what practicing engineers do is design, or is analylsis done in support of design. Even engineers and scientists who perform research must often design apparatus in the course of their research.
Engineering Design
What it is?
Design is simultaneously a creative, analytical, and cumulative process. While a certain amount of design can be taught in a lecture format, design is often best learned by hands-on experience. This course will introduce to the broader notion of engineering design, while primarily focusing on the design domain traditionally known as "mechanical design."
Engineering Design
What it is?
Most Design problems fall into one of the two categories: Product Design Systems Design Product Design is the creation, testing and manufacture of an item that usually will be mass produced, such as an appliance, a tool, or a toy.
Costs Production
Distribution
Function
Product Design
Market Needs
Profit
Sales
Engineering Design
What it is?
System Design combines products and their components into a unique arrangement and provides a method for their operation.
A residential building is a system of products consisting of heating and cooling, pluming, gas, electricity and other products.
Engineering Design
An engineering design is a type of drawing that is
What it is?
Technical in nature,
Used to fully and clearly define requirements for engineered items, and is usually Created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance (such as typefaces and line styles), size, etc.
Engineering Design
Design Process
Design is a process of creating a product or system to satisfy a set of requirements and final design is created at a profit or within the budget. The six steps of the design process are:
Identify 1
Design Process
Analyse 4
Engineering Design
Line Styles:
Common features
visible - are continuous lines used to depict edges directly visible from a particular angle.
hidden - are short-dashed lines that may be used to represent edges that are not directly visible. center - are alternately long- and short-dashed lines that may be used to represent the axes of circular features.
Engineering Design
Line Styles continued----:
Common features
cutting plane - are thick, medium-dashed lines, or thick alternately long- and double short-dashed that may be used to define sections for section views. section - are thin lines in a parallel pattern used to indicate surfaces in section views resulting from "cutting." Section lines are commonly referred to as "cross-hatching."
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Engineering Design
Line Styles continued----:
Black = object line and hatching Red = hidden line Blue = center line Magenta = cutting plane
Common features
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Engineering Design
Views and projections
Graphical projection is a protocol by which an image of an imaginary three-dimensional object is projected onto a plane surface by the use of imaginary "projectors".
Graphical projection contains three broad categories each
with its own protocol:
orthographic oblique , and perspective
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Engineering Design
used. Why?
To show all necessary features of an object, multiple views are
Describing three-dimensional objects in words are difficult Drawing any object as a three-dimensional pictorial is difficult
To make drawing such objects less difficult, engineers devised a standard system, called Orthographic Projection, for showing objects in different views.
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Engineering Design
Orthographic projections
Gaspard Monge (1746 - 1818) French mathematician and engineer.
Descriptive Geometry
...now called: Orthographic Projection.
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Engineering Design
Orthographic projection - show the object as it looks from the front, right, left, top, bottom, or back. Separate views represent the object at 90 degrees intervals as the viewer moves about it.
Figure 13.2, 13.3 and 13.4
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Engineering Design
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Engineering Design
Orthographic projection The maximum number of principal views in orthographic projection is six. These views must be sketched in their standard position. Seldom is an object so complex that it requires six orthographic views. Most objects are adequately describe with three orthographic views- usually the top, front and right-side views.
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Engineering Design
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Engineering Design
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Engineering Design
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Engineering Design
"box" around the object:
Views may be thought of as being projected onto planes that form a transparent
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Engineering Design
Orthographic projection is used to prepare precise, scaled and clearly presented
drawings from which the object depicted can be manufactured.
Figure 14.1 and 14.3
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Engineering Design
Alignment
of views
Align views with each other as this reduces the number of dimensions
required as the views are shared between different projections.
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Engineering Design
Selection
of views
Select the sequence of views with the fewest hidden lines
Engineering Design
schemes:
The views are positioned relative to each other according to either of two
First-angle or Third-angle projection.
First Angle projection: The object placed in the first quadrant
Third Angle projection: The object placed in the third quadrant

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Engineering Design
Fourth quadrant
First quadrant
Third quadrant
Second quadrant
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Engineering Design
First Angle projection.
Third Angle projection.

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Engineering Design
First angle projections
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Engineering Design
Third angle projections
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Engineering Design
Difference between First and Third angle projections
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Engineering Design

They differ only in the position of the plan, front and side views First Angle Eye>Object>Image Third Angle Eye>Image>Object
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Engineering Design
This first-angle projection arrangement of views is considered satisfactory in most European drafting practice. In the United States, it is considered illogical because the top view 32 is below the front view.
Engineering Design
Which is the best front view
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Engineering Design
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Engineering Design
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Engineering Design and CAD

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Engineering Design and CAD

Dr Sanjay Sharma PhD

Automatic control and systems engineering department, University of Sheffield

Engineering Design and CAD

: 20 : Coursework 1 (40%) + Coursework 2 (60%)

Minimum pass mark for the module : 40%

Views and projections

Views and projections

To show all necessary features of an object, multiple views are

Gaspard Monge (1746 - 1818) French mathematician and engineer.

Views and projections

Figure 13.2, 13.3 and 13.4

Views and projections

Views and projections

Views and projections

Views and projections

Views and projections

Orthographic projection is used to prepare precise, scaled and clearly presented

drawings from which the object depicted can be manufactured.

Figure 14.1 and 14.3

Select the sequence of views with the fewest hidden lines

First-angle or Third-angle projection.

First Angle projection: The object placed in the first quadrant

Third Angle projection: The object placed in the third quadrant

First Angle projection.

Third Angle projection.

Difference between First and Third angle projections

Difference between First and Third angle projections

Difference between First and Third angle projections

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