Computer Aided Electrical Drawing

COMPUTER AIDED ELECTRICAL DRAWING

Published by:

POLITEKNIK SULTAN HAJI AHMAD SHAH
25350 KUANTAN, PAHANG DARUL MAKMUR
COPYRIGHT©2020, Politeknik Sultan Haji Ahmad Shah

Perpustakaan Negara Malaysia Cataloguing-in-Publication Data
Wan Ghani Wan Pi, 1968-
COMPUTER AIDED ELECTRICAL DRAWING / WAN GHANI WAN PI,
MOHD YUSOF ZAKARIA, TG BESARUDDIN SH TG YAAKOB.
Mode of access: Internet
eISBN 978-967-0778-67-9
1. AutoCAD--Handbooks, manuals, etc.
2. Computer-aided design--Handbooks, manuals, etc.
3. Government publications--Malaysia.
4. Electronic books.
I. Mohd. Yusof Zakaria, 1966-. II. Tg. Besaruddin Sh. Tg. Yaakob, 1966-.
III. Title.
620.00420285

Materials published in this book is under the copyright of the Politeknik Sultan Haji Ahmad Shah. All
rights reserved. No part of this publication may be reproduced or distributed in any form of by means,
electronic, mechanical, photocopying, recording, or otherwise or stored in a database or retrieval
system without the prior written permission of the publisher.
Printed in Malaysia by:
Xtreme Techno Trading
No.6, Kg. Selamat Baru,
Bangunan LKNP
25050 Kuantan
Pahang Darul Makmur

eISBN 978-967-0778-67-9

Computer Aided Electrical Drawing

PREFACE

This book provides a step-by-step introduction to AutoCAD with commands presented
in the context of each chapter. In eleven clear and comprehensive chapters, authors
guide readers through all the important commands and techniques in AutoCAD 2018,
for 2D drawing to complete electrical engineering schematics and finally finishing with
plotting output. In each lesson, the author provides step-by-step instructions with
frequent illustrations showing exactly what appears on the AutoCAD screen. Later,
individual steps are no longer provided, and readers are asked to apply what they have
learned by completing sequences on their own. A carefully developed pedagogy
reinforces this cumulative-learning approach and supports readers in becoming skilled
AutoCAD users. Tutorial Guide to AutoCAD 2018 begins with the Getting Started
chapters that include information to get readers of all levels prepared for the tutorials.
The author includes tips that offer suggestions and warnings as you progress through
the tutorials. Key Terms and Key Commands are listed at the end of each chapter to
recap important topics and commands learned in each tutorial. Also, a glossary of
terms and Commands Summary list the key commands used in the tutorials. Each
chapter concludes with end of chapter tutorial providing challenges to a range of
abilities in mechanical, electrical, and civil engineering as well as architectural
problems.

Author:

WAN GHANI BIN WAN PI
Electrical Eng. Department, Kota Bharu Polytechnic, Kelantan
Bachelor of Education (Hons) (Electrical Engineering)
Autocad Certified Professional, Autodesk, USA

HJ. MOHD YUSOF BIN ZAKARIA
Director, Community College Kuantan, Pahang
Bachelor of Education (Electrical Engineering)
Autocad Certified Professional, Autodesk, USA

TENGKU BESARUDDIN SHAH BIN TENGKU YAAKOB
Mechanical Eng. Department, Sultan Haji Ahmad Shah Polytechnic
Bachelor of Engineering (Hons.) Mechanical, DmechE.
Autocad Certified Professional, Autodesk, USA

Computer Aided Electrical Drawing

Contents

01 INTRODUCTION OF AUTOCAD .......................................................................... 1
DEFINITION OF COMPUTER AIDED DESIGN (AUTOCAD) ................................. 1
DIFFERENCES BETWEEN AUTOCAD AND CONVENTIONAL DRAWING .......... 1
ADVANTAGES OF AUTOCAD OVER CONVENTIONAL TECHNICAL DRAWING 1

02 THE COMMANDS IN AUTOCAD......................................................................... 2
KEYBOARD ............................................................................................................ 2
BUTTON MENU ...................................................................................................... 2
AutoCAD 2018 ICON MENU ................................................................................... 3

03 CREATING A NEW DRAWING............................................................................. 6
SAVING A DRAWING ............................................................................................. 7

04 DRAWING SETUP ................................................................................................ 8
GRID AND SNAP .................................................................................................... 8
UNITS ..................................................................................................................... 9
The length options................................................................................................ 9
LIMITS................................................................................................................... 10

05 DRAW COMMAND ............................................................................................. 12
LINE ...................................................................................................................... 12
Exercise 1 .......................................................................................................... 15
POLYLINE............................................................................................................. 16
TEXT, DTEXT ( Dynamic text ) AND MTEXT (Multiline text) ................................ 18
Assignment 1b ................................................................................................... 21
CIRCLE ................................................................................................................. 22
ARC....................................................................................................................... 25
DONUT ................................................................................................................. 27
POLYGON ............................................................................................................ 28
Assignment 2 ..................................................................................................... 30
POINT ................................................................................................................... 34
Assignment 3a ( Electronic component )............................................................ 36
Assignment 3b ( Electrical parts )....................................................................... 37

06 MODIFY COMMAND .......................................................................................... 41
ERASE .................................................................................................................. 41
MOVE.................................................................................................................... 42
COPY .................................................................................................................... 43
ROTATE................................................................................................................ 45

Computer Aided Electrical Drawing

BREAK .................................................................................................................. 46
TRIM ..................................................................................................................... 48
SCALE .................................................................................................................. 49
MIRROR................................................................................................................ 51
ARRAY.................................................................................................................. 52
EXTEND................................................................................................................ 54
FILLET .................................................................................................................. 55
CHAMFER ............................................................................................................ 56
OFFSET ................................................................................................................ 58
CHANGE............................................................................................................... 59
PEDIT.................................................................................................................... 59
OBJECT SNAPS ................................................................................................... 61
07 DISPLAY CONTROL........................................................................................ 64

ZOOM ................................................................................................................ 64
ALL..................................................................................................................... 65
CENTER ............................................................................................................ 65
DYNAMIC........................................................................................................... 65
EXTENTS........................................................................................................... 66
PREVIOUS......................................................................................................... 66
SCALE (X/XP) .................................................................................................... 66
WINDOW ........................................................................................................... 67
PAN.................................................................................................................... 67
REDRAW ........................................................................................................... 68
REGEN .............................................................................................................. 68
08 BLOCK, WBLOCK AND INSERT BLOCK ........................................................ 69
BLOCK ............................................................................................................... 69
WBLOCK ( write block ) ..................................................................................... 71
INSERT BLOCK ................................................................................................. 72
MINSERT ........................................................................................................... 72
EXPLODE .......................................................................................................... 73
09 LAYER, LINETYPE AND COLOR .................................................................... 75
LAYER COMMANDS ......................................................................................... 75
HOW TO SET LINETYPES AND COLOR.......................................................... 78
10 DIMENSIONING............................................................................................... 81
IMPORTANCE AND BENEFITS OF DIMENSIONING DRAWINGS .................. 81
LINEAR .............................................................................................................. 83
RADIUS.............................................................................................................. 84

Computer Aided Electrical Drawing

DIAMETER......................................................................................................... 84
ALIGNED ........................................................................................................... 85
ANGULAR.......................................................................................................... 85
DIM STYLE AND VARIABLE ............................................................................. 86
11 PLOTTING ....................................................................................................... 89
PREPARATORY STEPS FOR PLOTTING ........................................................ 89
PLOT AREA ....................................................................................................... 90
REFERENCES......................................................................................................... 92

Computer Aided Electrical Drawing

1

01 INTRODUCTION OF AUTOCAD

DEFINITION OF COMPUTER AIDED DESIGN (AUTOCAD)
AutoCAD is a computer aided drafting and design software from Autodesk Inc. It is
widely used in various applications including all engineering fields.

DIFFERENCES BETWEEN AUTOCAD AND CONVENTIONAL DRAWING
Using AutoCAD
❖ Designs can be made quickly.
❖ Designers only need to make a simple sketch of the design.
❖ Drawings produced are consistent and mistakes can be minimized.
❖ All angles of a drawing can be shown.
❖ Changes to drawing can be made easily.
❖ Exact copies of drawings can be produced quickly.
❖ Objects can be viewed in 3D.
❖ Objects can be viewed as animation.

ADVANTAGES OF AUTOCAD OVER CONVENTIONAL TECHNICAL DRAWING
❖ Improves the productivity, efficiency, and accuracy of drawings
❖ Enables drawings to be created, checked, and edited quickly
❖ Improves the quality of products
❖ Retains uniformity in reproduction
❖ Minimizes storage space

HARDWARE COMPONENTS OF THE AUTOCAD SYSTEM
The hardware components of the AutoCAD system comprise the following :
❖ Monitor
❖ Central processing unit (CPU)
❖ Keyboard
❖ Mouse
❖ Plotter

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2

02 THE COMMANDS IN AUTOCAD

KEYBOARD
Type in the command at the command line and press Enter or Space Bar.

Type
here

BUTTON MENU
The menu is for a pointing device with multiple buttons. A point may be specified using
a pointing device, such as a mouse or a digitizer puck. The coordinates of the selected
point are then entered when the ‘PICK’ button of the pointing device is pressed.

Enter

Pick or
Select

Zoom

Computer Aided Electrical Drawing

AutoCAD 2018 ICON MENU 3
Info Center
Panel Titles

Application
Menu

Ribbon

Drawing Crosshair
Area

View
NaviCguabtioen
Bar

UCS

Command Status
Line Bar

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4

The buttons at the left-hand end of the status bar

A number of buttons at the left-hand end of the status bar can be used for toggling
(turning on/off) various functions when operating within AutoCAD 2019. A click on a
button turns that function on; if it is off, a click on a button turns the function back on.
Similar results can be obtained by using function keys of the computer keyboard (keys
F1 to F10).

Snap Mode also toggled using the F9 key: when snap on, the cursor under mouse
control can only be moved in jumps from one snap point to another.

Grid Display also toggled using the F7 key: when set on a series of grid points
appears in the drawing area.

Ortho Mode also toggled using the F8 key: when set on, lines etc. can only be drawn
vertically or horizontally.

Polar Tracking also toggled using the F10 key: when set on, a small tip appears
Showing the direction and length of lines etc., in degrees and units.

Object Snap also toggled using the F3 key: when set on an OSnap icon appears at
the cursor pick box.

Object Snap Tracking when setting on, lines etc., can be drawn at exact coordinate
points and precise angles.

Allow/Disallow Dynamic UCS also toggled by the F6 key. Used when constructing
3D solid models.

Dynamic Input also toggled by F12. When set on, the x,y coordinates and prompts
show when the cursor hairs are moved.
Show/Hide Lineweight when setting on, lineweights show on screen. When setting
off, lineweights only show in plotted/printed drawings.

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5
Quick Properties a right-click brings up a pop-up menu, from which a click on
Settings… causes the Drafting Settings dialog to appear.
The buttons at the right-hand end of the status bar
Another set of buttons at the right-hand end of the status bar is shown below. The
uses of some of these will become apparent when reading future pages of this book.
A click on the downward- facing arrow near the right-hand end of this set of buttons
brings up the Application Status Bar Menu from which the buttons in the status bar
can be set on or off.

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03 CREATING A NEW DRAWING

AutoCAD and AutoCAD LT create a blank drawing upon startup, but it’s a good idea
to select the drawing template that you want to use at startup and not rely on the one
that AutoCAD or AutoCAD LT creates for you. To create a new drawing, follow these
steps:
1. Click Start Drawing.

For new drawing, click Start Drawing

A new drawing is created for you based on the drawing template selected.

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SAVING A DRAWING
Before going further, it is as well to know how to save the drawings constructed when
answering examples and exercises in this book. When a drawing has been
constructed, left click on the Save icon Standard Annotation toolbar. The Save
Drawing As dialog appears.

Unless you are the only person to use the computer on which the drawing has been
constructed, it is best to save work to a pen drive, usually held in the drive E: To save
a drawing to a pen drive in drive E:
1. Place a pen drive in drive E:
2. In the Save in field of the dialog, click the arrow to the right of the field

and from the pop-up list drive [E:].
3. In the File name: field of the type a name. The file name extension “.dwg”

does not need to be typed – it will be added to the file name.
4. Left click the Save button of the dialog. The drawing will be saved with

the file name extension .dwg – the AutoCAD fi le name extension.

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04 DRAWING SETUP

GRID AND SNAP
1. On the status bar, pick snap settings.
2. The Drafting Settings dialog box appears below.
3. Select the Snap On (F9) and Grid On (F7) options.

4. In the Snap Spacing area, select Equal X and Y Spacing if it’s not selected.
5. In the Snap Spacing area, double-click the Snap X Spacing text box,

and then type 1 and press Tab. Because you selected the Equal X and Y
Spacing option, the value in the Snap Y Spacing text box was updated to match
the value entered in the Snap X Spacing text box.
6. In the Grid Spacing area, double-click the Grid X Spacing text box, and then
type 1 and press Tab. The value in the Grid Y Spacing text box is updated to
match the value in the Grid X Spacing text box.
7. In the Snap Type area, select Grid Snap and then select Rectangular
Snap if they are not already selected.
8. Click OK.

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UNITS

There are two methods of doing this.

1. Type Units at the command prompt. OR

2. Click FORMAT UNITS from the Pull-down menu (Autocad Classic ).

The length options

Architectural Feet, inches, and fractional inches, as in 12´6.˝. You would enter
Engineering
this as 12´6 1/2˝ with a space between the 6 and the 1/2.

Feet and decimal inches, as in 12.5´ or 12´6.5˝. You would enter

this as 12´6.5˝.

Decimal Whole and decimal units that can be anything (metric distances,

decimal inches, decimal feet, or decimal miles, for example).

Fractional Whole and fractional units that can be anything (fractional metric

distances, fractional inches, feet, or miles, for example).

Scientific Scientific notation for distances. Units can be anything

(meters, angstroms, miles, astronomic units, parsecs, or

light-years, for example)

The angle options:

Decimal Degrees Whole and decimal degrees of angle. Deg/Min/Sec

Degrees, minutes, and seconds of angle.

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10

Grads Angles specified in grads. For example, you would specify 45°
Radians of an angle by entering 50g.
Surveyor’s Angles specified in radians. For example, you would specify
Precision 45° by entering 0.785r.
Angles specified in degrees from north or south to east or
Direction west, as in Units N45dE.
The Precision option lets you control how AutoCAD reports length
Clockwise and angle values. This option does not actually affect
LIMITS the precision of the objects in the drawing. For example, if you
select Decimal as the length type and 0.0 for the precision,
AutoCAD displays a distance of 1.2 for the true distance of
1.167. If you choose 0.000 for the Precision option, you will
see the full distance of 1.167 whenever AutoCAD displays a
distance.
By default, AutoCAD assumes that 0° is a horizontal direction
from left to right. For example, 90° is directly vertical, and 180° is
a horizontal direction from right to left. Angle values increase from
0° in a counterclockwise fashion. The cardinal directions and their
degree values in a default AutoCAD setup. If your drawing
requires a different direction for 0°, you can use the Direction
option to choose an angle. When you click the Direction button,
the Direction Control dialog box opens. Click one of four radio
buttons to select the 0° direction from the four cardinal directions.
If your desired 0° direction does not conform to the cardinal
directions, you can specify an angle numerically or graphically by
selecting the other option.
By default, angle values increase counterclockwise, but you
can change this to clockwise by selecting the Clockwise
option in the Angle group of the Drawing Units dialog box.

There are two methods of doing this.
1. Type Limits at the command prompt. OR
2. Click FORMAT LIMITS from the Pull-down menu (Autocad Classic ).

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11

The sample of paper size 594mm ( 594,420 )
(0,420)
( 420,297 ) A2
(0,297) 420mm
Upper right corner
297mm ( 297,210 )
(0,210) 297mm
A3
420mm

A4 210mm

( 0, 0 )

( 297,0 ) ( 420,0 ) ( 594,0 )

Lower left corner
Example 1 :
Command: limits
Reset Model space limits:
Specify lower left corner or [ON/OFF] <0.0,0.0>: 0.0
Specify upper right corner <0.0,0.0>: 420,297

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05 DRAW COMMAND

LINE
The line is the most fundamental drawing entity. It can be drawn with various linetypes.
There are two methods of doing this.
3. Type Line or just L at the command prompt Or
4. Click Line from the Draw icon.

specify first point
:

Specify next point or [Undo] :

Once a command has been entered, in many instances, AutoCAD requires additional
input. The input may be in the form of coordinates, numeric value, displacements,
modifiers, file names, etc. The following are four methods in which data that are points
may be entered.
NOTE: Dynamic Input ( F12) OFF

1.0 Absolute Coordinate
A point can be specified by typing the X and Y coordinates.

Example :

Command : Line 60,120 160,120

first point : 60,60

next point : 160,60 60

next point : 160,120

next point : 60,120

next point : 60,60 @ c 60,60 100 160,60

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13

2.0 Relative Coordinate

A point can be specified as the distance from the last coordinate entered. Type

@ prior to the X and Y distances. @ means with reference to the last point.

Format :

@ X distance, Y distance

Y distance

Example : @-100,0 X distance
Command : Line 60,130 @0,60
first point : 60,130
next point : @100,0 60
next point : @0,60 100 @100,0
next point : @-100,0
next point : 60,130 @ c

3.0 Polar Coordinate
A point may be specified as the distance and the angle from the last coordinate
(point) entered.
90o

180 o 0o

270 o @-90 o

format :

@ distance < angle

Example :

Command : Line @100<180 @60<90

first point : 60,200 60
100 @100<0
next point : @100<0
Computer Aided Electrical Drawing
next point : @60<90

next point : @100<180

next point : @60<270 60,200

14

4.0 Pointing
You may type the line coordinates using the keyboard or click the first point using

the mouse.

• Click any point in the drawing area. AutoCAD prompt specifies the next point

or [Undo].

• Move the mouse pointer to a second point and click button 1 of the mouse and

enter.

First point

( go to page 40 – Erase command ) Second
point

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15

Exercise 1
By using point entry commands, using Line Commands to draw the following figures:

38 60

20 50
30
3
0 O

60 8
0

200,16 27
0 43

10
00

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POLYLINE
A polyline is a connected sequence of line segments created as a single object. You
can create straight Line segments, Arc segments, or a combination of the two.
There are two methods of doing this.

1. Type Pline or just PL at the command prompt Or
2. From the Draw icon, choose the Polyline.

Specify start point :

Arc Halfwidth Length Undo Width

endpoint of arc: starting half-width: length of line: Starting Width:
Ending width:
ending half-width:

Specify next point :

Ending width

Half-width

Endpoint of Arc

Specify first point Length of line Starting Width

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Example 1 :

Command : Pline

Specify start point : 60,60

Specify next point or ( arc/halfwidth/length/undo/width) : w

Starting width : 2

Ending width : 2

Specify next point or ( arc/halfwidth/length/undo/width) : @100<0

Specify next point or ( arc/halfwidth/length/undo/width) : @60<90

Specify next point or ( arc/halfwidth/length/undo/width) : @100<180

Specify next point or ( arc/halfwidth/length/undo/width) : close

@100<180 @60<90

60

Example 2 : 60,60 100 @100<0

Command : Pline

Specify start point : 60,130

Specify next point or ( arc/halfwidth/length/undo/width) : w

Starting width : 10

Ending width : 10

Specify next point or ( arc/halfwidth/length/undo/width) : @50<0

Specify next point or ( arc/halfwidth/length/undo/width) : w

Starting width : 15

Ending width : 0

Specify next point or ( arc/halfwidth/length/undo/width) : @20<0

Width=10

15

60,130

50 20
( go to page 62,65 – Zoom and Pan command )

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18

Assignment 1a

Draw the block name below with DRAW and POLYLINE command by using all the
coordinates. This block name using A3 size ( 420 mm x 297 mm ).

TEXT, DTEXT ( Dynamic text ) AND MTEXT (Multiline text)

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19

Single-line text is created with the DTEXT command. TEXT is now an alias for the
DTEXT command; typing either at the command line runs DTEXT. You can define a
few properties such as a single font or a preset height in a text style, but MTEXT can
formatting multiline text, changing things such as font, size, and color, and structuring
text in columns.

Text/Dtext Mtext

Style Formatting Paragraph Insert Options

Style Justify

Align Fit Center Middle Right

1st 1st Center Middle pt Right
point point pt Endpt
2nd 2nd
point point

( go to page 41 & 42 – Move & Copy command )
Example 1 :
Command: _mtext

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20

Specify first corner: pick first corner
Specify opposite corner or [Height/Justify/Line
spacing/Rotation/Style/Width/Columns]:

First corner type text here

Example 2 :
Command: text
Current text style: "Standard" Text height: 3.0 Annotative: No
Specify start point of text or [Justify/Style]: pick a start point
Specify height <0>: 5
Specify rotation angle of text <0>: 0

Height = 5

AUTOCAD ROTATION = 0

Start point

( go to page 58 – Pedit command )

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Assignment 1b
Use Text or Dtext or Mtext command to fill all the text at the block name ( open an
existing drawing Assignment 1 ) with the related size of the text shown below.

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22

CIRCLE

A circle can be drawn with various linetypes.
There are two methods of doing this.
1. Type Circle or just C at the command prompt OR
2. Click Circle from the Draw icon

Center point 3P 2P TTR TTT

Radius Diameter 1st point 1st point 1st tangent 1st Tangent
spec 2nd Tangent
2nd point 2nd point 3rd Tangent
2nd tangent
3rd point spec

Radius

2P TTR
3P TTT

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23

Example 1 :
Command: Circle
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:100,100
Specify radius of circle or [Diameter] <0.0000>: 30

Radius =30

Example 2 :
Command: Circle
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:100,170
Specify radius of circle or [Diameter] <0.0>: D
Specify diameter of circle <0.0>: 60

Diameter =60

Example 3 :

Command: Circle

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 3P

Specify the first point on the circle: 170,130 1st Point
X

Specify the second point on circle: 170,70

Specify the third point on circle: 200,100 2 nd
Point
X

3rd Point
X

Computer Aided Electrical Drawing

24

Example 4 :
Command: Circle
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 2P
Specify the first point on the circle: 170,200
Specify the second point on circle: 170,140

1st point
x

x
2nd point
Example 5 :
Command: Circle
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: type TTR or T
Specify point on object for first tangent of circle : ( select 1st tangent spec )
Specify point on object for second tangent of circle : (select 2nd tangent spec )
Specify radius of circle <0.0> : 30

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25

( go to page 60 – Object Snaps commands, go to page 66- Redraw & Regen
command )
ARC
The Arc is a partial circle that can be drawn using any of the different options in the
pull down menu. It can also be drawn with various linetypes.
There are two methods of doing this.
1. Type Arc or just A at the command prompt OR
2. Click Arc from the Draw toolbar.

R

S – Start point A - Angle
C – Center L – Length of chord
E – End R – Radius of the arc
D – Direction

3 point SCE SCA SCL SEA SED SER CSE CSA CSL

1st point Start Start Start Start Start Start Center Center Center

2nd Center Center Center End End End Start Start Start
point Angle Length Angle End Angle Length
Directio Radiu
3rd point End ns

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26

Example 1 :

Command : Arc ( 3 Point ) 70,150

Specify start point of arc or [Center]: 100,70

Specify second point of arc or [Center/End]: 130,120
130,120

Specify end point of arc: 70,150

Example 2 : 100,70

Command: Arc ( Start, Center, Angle ) 230,100 90
Specify start point of arc: 230,100 80
Specify center point of arc: @80<0
Specify included angle: -90

( go to page 44 – Rotate command )

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27

DONUT

The DONUT command is used to create a thick or solid circle. The inside diameter is
used to determine the hole of the doughnut. Use an inside diameter of zero to create
a solid circle; use a larger diameter to create a ring.

There are two methods of doing this.

1. Type Donut or just type DO at the command prompt OR

2. Click Donut from the Draw toolbar.

Donut 30

Inside diameter : 40 100,100

Outside diameter Computer Aided Electrical Drawing
:

Center of donut

Example 1:

Command: Donut
Specify inside diameter of donut: 30
Specify outside diameter of donut: 40
Specify center of donut: 100,100

28

Example 2:

Command: Donut
Specify inside diameter of donut : 0
Specify outside diameter of donut: 40
Specify center of donut: 100,150

40 100,150

POLYGON

A polygon is a polyline object. AutoCAD draws polyline with zero width and no tangent
information. Creating polygons is a simple way to draw squares, equilateral triangles,
octagons and so on.

There are two methods of doing this.
1. Type Polygon or POL at the command prompt OR

2. From the Draw toolbar, choose the Polygon flyout.

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29

Triangle Square
Hexagon
Pentagon

The number of sides of the polygon, for example, pentagon = 6, hexagon = 5 and etc.
In the first two illustrations, the center of Polygon and defines the radius length, which
is specified with the pointing device or coordinate.

Example 1:
Command: _polygon Enter number of sides: 6
Specify center of polygon or [Edge]: 120,100
Enter an option [Inscribed in circle/Circumscribed about circle] <C>: I
Specify radius of circle: 40

Example 2:
Command: _polygon Enter number of sides : 6
Specify center of polygon or [Edge]: 240,100
Enter an option [Inscribed in circle/Circumscribed about circle] <I> : C
Specify radius of circle: 40

( go to page 45 & 47 – Break & Trim command )

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30

Assignment 2

`

Computer Aided Electrical Drawing

31

ELLIPSE
The shape of an ellipse is determined by two axes that define its length and width. The
longer axis is called the major axis, and the shorter one is the minor axis.
There are two methods of doing this.
1. Type Ellipse or type EL at the command prompt.
2. From the Draw icon, choose the Ellipse flyout.

Center Axis/End Elliptical Arc
Specify center Specify axis endpoint Specify axis endpoint
Specify endpoint Specify other endpoint Specify other endpoint
Specify distance
Specify distance Specify distance
Specify start angle
Specify end angle

Computer Aided Electrical Drawing

32

Example 1:
Command: _ellipse ( Center )
Specify center of ellipse: 100,150
Specify endpoint of axis: 150,190
Specify distance to other axis or [Rotation]: 20

Example 2:
Command: _ellipse ( Axis/End )
Specify axis endpoint of ellipse or [Arc/Center]: 260,190
Specify other endpoint of axis: 205,190
Specify distance to other axis or [Rotation]: 30

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Example 3:
Command: _ellipse ( Arc )
Specify axis endpoint of elliptical arc or [Center]: 300,130
Specify other endpoint of axis: 350,130
Specify distance to other axis or [Rotation]: 50
Specify start angle or [Parameter]: -90
Specify end angle or [Parameter/Included angle]: 90

Start angle = -90 @ 270 and end angle = 90 is clockwise
Start angle = 90 and end angle = -90 @ 270 is anti-clockwise

( go to page 48,50, 51 & 53 – Scale, Mirror, Array and Extend command )

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POINT
Point objects are useful as nodes or reference points. They are temporary objects you
create to help you draw accurately.
There are two methods of doing this.
1. Type Point at the command prompt.
2. From the Draw icon, choose the Point flyout.

Multiple Point Point Measure
Specify a point Select object
Devide length of segment
Select object

number of
segments

Line

You can set the style of the points and their size relative to the screen or in absolute
units. Changing the style of points:
❖ Makes them more visible and easier to differentiate from grid dots
❖ Affects the display of all point objects in the drawing
❖ Requires using REGEN to make the change visible

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To set point style and size :
1. From the Home Tab, Utility group, choose Point Style.
2. In the Point Style dialog box, select a point style.
3. Under Point Size, specify a size, either relative to

the screen origin absolute units.
4. Choose OK.

Example 1 : point style

Command: point
Current point modes: PDMODE=4 PDSIZE=20.0
Specify a point: select point, select point 2 ( to stop press esc )

Example 2 : number of segments = 4
Command: divide
Select object to divide: pick
Enter the number of segments or [Block]: 4

Example 3 :
Command: measure
Select object to measure:
Specify length of segment or [Block]: 20

20 20

( go to page 54, 55, 57 & 58 – Fillet, Chamfer, Offset and Change command )

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Assignment 3a ( Electronic component )
By using all commands, draw all the components below and use an existing drawing
name: Assignment 1a.

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Assignment 3b ( Electrical parts )
By using all commands, draw all the electrical parts below and use an existing drawing
name: Assignment 1a.

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Legend Electrical parts
Electronic components

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06 MODIFY COMMAND

ERASE

There are many ways to delete objects from your drawing and clean up the display
There are two methods of doing this.
1. Type Erase or just E at the command prompt.
2. Click Erase from the Modify icon.

ERASE

Select object : Pick object or select by window

Example 1 :

Command : erase
Select objects: pick object and press Enter (when you finish selecting
objects)

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MOVE
The Move command allows one or more entities to be moved to any location in the
drawing.
There are two methods of doing this.
1. Type Move or just M at the command prompt.
2. Click Move from the Modify toolbar.

MOVE

Select object :
Base point or displacement : pick point or type
coordinate

Second point of displacement : pick point or type
coordinate

Example 1 :
Command: Move
Select objects: pick object
Base point or displacement : (select center of circle )
Second point of displacement: @10<0 or pick point at drawing area

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COPY
The Copy command allows you to make a copy or copies of an entity or a group at
any location in the drawing.
There are two methods of doing this.
1. Type Copy or just Co at the command prompt.
2. Click Copy Object from the Modify icon.

COPY

Select object :

Single copy Multiple copy

Select object : Select object :

Base point or displacement: Base point or
Second point of displacement: displacement:

Second point of
displacement:

Second point of
displacement:

Second point of
displacement:

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Example 1 :
Command: copy
Select objects: pick object
Current settings: Copy mode = Multiple
Specify base point or displacement : select CENter (OSNAP)
Specify second point or <use first point as displacement>: @10<0
Specify second point or [Exit/Undo] <Exit>:

Example 2 :
Command: copy
Select objects: pick object
Current settings: Copy mode = Multiple
Specify base point or displcement: select CENter ( OSNAP)
Specify second point : @10<0 (copy 1)
Specify second point or [Exit/Undo] <Exit>: @10,5 ( copy 2)
Specify second point or [Exit/Undo] <Exit>: @10,-5 (copy 3)

Computer Aided Electrical Drawing