ERT 249ERT 249CComputer Aided Design omputer Aided Design

(CAD)(CAD)For Biosystem For Biosystem EngineeringEngineering

Prepared By:Prepared By:

Samera binti Samsuddin SahSamera binti Samsuddin Sah

Email: samera@unimap.edu.myEmail: samera@unimap.edu.my

Phone: 04-9798835/016-Phone: 04-9798835/016-41445374144537

Learning OutcomesLearning Outcomes

Assessment and GradingAssessment and Grading

HistoryHistory

Evolution of CADEvolution of CAD

IntroductionIntroduction

Engineering DrawingEngineering Drawing

Computer Aided Design Computer Aided Design (CAD)(CAD)

Computer Aided DesignComputer Aided Design

Computer software

Geometric Modelling

CAD

Tools in design

process

The integration of computer software and geometric model to serve the design process

Design ProcessDesign Process

Contribution of CAD in Contribution of CAD in designdesign

Design FormatsDesign Formats

3D Geometric Primitives3D Geometric Primitives

CAD Software ProductCAD Software Product

Advantages of CADAdvantages of CAD

1.

2.

3.

4.

Advantages of CAD

CAD CapabilityCAD Capability

Limitation of CADLimitation of CAD(within scope of drawing creation)(within scope of drawing creation)

Limitation of CADLimitation of CAD(within scope of drawing (within scope of drawing

creation)creation)

Limitation of CADLimitation of CAD(within scope of drawing (within scope of drawing

interpretation)interpretation)

Basic Information Basic Information Included in a DrawingIncluded in a Drawing

Projected ViewsProjected Views

A Table ExampleA Table Example

DimensionsDimensions

A Dimensioning ExampleA Dimensioning Example

More basic informationMore basic information

ISO International Standards Organization

Standard CodeStandard Code

ANSI American National Standard InstituteUSA

JIS Japanese Industrial StandardJapan

BS British StandardUK

AS Australian StandardAustralia

Deutsches Institut für NormungDINGermany

Country Code Full name

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Basic Line Types Basic Line Types

Types of Lines AppearanceName according

to application

Continuous thick line Visible line

Continuous thin line Dimension line

Extension line

Leader line

Dash thick line Hidden line

Chain thin line Center line

Visible linesVisible lines represent features that can be seen in the

current view

Meaning of LinesMeaning of Lines

Hidden linesHidden lines represent features that can not be seen in

the current view

Center lineCenter line represents symmetry, path of motion, centers

of circles, axis of axisymmetrical parts

Dimension and Extension linesDimension and Extension lines indicate the sizes and

location of features on a drawing

ExampleExample : : Line conventions in engineering drawingLine conventions in engineering drawing

Line ConventionLine Convention

Precedence of coincide lines.

Hidden line drawing.

Center line drawing.

Precedence of LinePrecedence of Line

Visibleline

Visibleline

Order ofimportance

Hiddenline

Hiddenline

Centerline

Centerline

Hidden Line PracticeHidden Line Practice

Hidden line should join a visible line, except itextended from the visible line.

Correct

No !

Join

Leavespace

Correct No !

Hidden line should join a visible line, except itextended from the visible line.

Leavespace

Leavespace

Hidden Line PracticeHidden Line Practice

Hidden line should intersect to form L and Tcorners.

Correct

No !

L T

Hidden Line PracticeHidden Line Practice

Hidden arcs should start on a center line.

Hidden Line PracticeHidden Line Practice

Centre Line PracticeCentre Line Practice

In circular view, short dash should cross at the

intersections of center line.

For small hole, center line is presented as thin

continuous line.

Center line should not extend between views.

Leave space Leave space

Leave the gap when centerline forms a

continuation with a visible or hidden line

Leavespace

Leavespace

Leavespace

Leavespace

Center line should always start and end with

long dash.

Centre Line PracticeCentre Line Practice

ScalingScaling

Drawing SheetDrawing Sheet

•Trimmed paper of a size A0 ~ A4.

•Standard sheet size (JIS)

A4 210 x 297

A3 297 x 420

A2 420 x 594

A1 594 x 841

A0 841 x 1189

A4

A3

A2

A1

A0

(Dimensions in millimeters)

Drawing space Drawingspace

Title block

d

d

c

c

cBorder lines

1. Type X (A0~A4) 2. Type Y (A4 only)

Orientation of drawing sheetOrientation of drawing sheet

Title block

Sheet size c (mm) d (mm) A4 10 25 A3 10 25 A2 10 25 A1 20 25 A0 20 25

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