INTRODUCTION TO AUTOCAD

This Topic will discuss one of ICT software used for Preparation of Architectural Drawings
by using AutoCAD. The AutoCAD version used here 2007, however you can apply them
within any version of AutoCAD with slightly changes you may meet.

1. Introduction

 AutoCAD Interface
 Setting up the Drawing Area
 Specifying Drawing Units
 Specifying Paper size
 Specifying Drawing Scale
 Accessing AutoCAD Commands
 Using Toolbars
 Using Menus
 Using Command line
 Drafting Settings
 Object Snap Settings
 Grid Settings
 Coordinates Settings

2. Drawing with AutoCAD

 Freehand method
 Direct Distance
 Drawing Basic Shapes
 Rectangles
 Circles
 Polygons
i. Inscribe
ii. Circumscribe
 Geometric Construction

3. Editing the Drawing

 Basic Editing Commands
 Copy
 Move
 Erase/delete
 Scale
 Explode
 Chamfer
 Fillet
 Offset
 Trim
 Hatch

 Creating Multiple Entities with Array

 Rectangular Array

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  Polar Array
 Fit to Path

4. Organising and Managing Drawing

 Using the Design Center

 Accessing Named Components
 Creating and Inserting Blocks
 Annotations
 Layers

5. Plotting

 Model
 Layout
 ViewPorts
 Named Views

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1. Introduction
AutoCAD is general purpose Computer Aided Design (CAD) program for
preparing two-dimensional drawings and three-dimensional models. It
provides a full range of drafting tools that let you create accurate and
realistic images that meet the ANSI standards for drafting. You can retrieve
and analyse the information in your AutoCAD drawings to generate Reports,
Bills of materials, Cost effectiveness studies, numerical control data and
much more.

This lesson will describe the AutoCAD screen, command entry methods and
dialog box usage, creating and opening a drawing and exiting AutoCAD

AutoCAD 2022 Interface

When you first start AutoCAD, the initial screen contains the menu bar at the
top, the status bar at the bottom, the drawing window and several toolbars.
Toolbars contain icons that represent commands.

The Ribbon

This is a list of tools used for drawing, modifying, annotating and layering the
objects

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AutoCAD and Paper

Setting up the Drawing area

In other window programs you can use any scaling factor you want to
squeeze content onto paper. You have probably an excel spreadsheet with
some odd scaling factor such as 82.5% of full size because that is what it
took to squeeze the content onto a single sheet of paper while keeping the
size of text as large as possible.

In drafting, your printout needs to use a specific widely accepted scaling

factor such as 1:100 to be useful and understandable to others.

Before you drawing setup process, you need to make decisions about your
drawing. These three questions are absolutely critical. If you don’t answer
them, or you answer them wrong, you will probably need to do lots of
reworking of the drawing later:

 What drawing units will you use?

 At what scale or scales will you plot it?
 On what size of paper does it need to fit?

Choosing Your Units

AutoCAD is extremely flexible about drawing units; it lets have them in your
way. Usually you choose types of units that you normally use to talk about
whatever you are drawing: fit and inches for a building in the United States,
millimetres for metric screw and so on.

During drawing setup you choose two units characteristics: a type of unit and
precision of measurement in the drawing unit dialog box. After you specify
the type of unit, you draw things on screen full size in those units just as
though as you were laying them out in the construction site.
Procedure:
1. Click on Format menu > Units
2. From displayed window specify the following parameters:
 Length - Decimal
 Precision - 0
 Angle - Decimal degrees
 Precision - 0
 Units to scale inserted content - Millimetres
 Base angle - East
3. Click OK

Weighing Your Scales

The next decision you should make before setting a new drawing is choosing
the scale at which you will eventually plot the drawing. This decision gives
you the drawing and drawing scale factor – two ways of expressing the same
relationship between the objects in the real world and objects plotted on
paper.

Table below lists some common architectural drawing scales using both
English and metric units. (Ratios such 1:200 are unit less. Building plans and
detail measurements often are expressed in millimetres, so you can think of

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1:200 as meaning “1 millimetre on the plotted drawing equals 200
millimetres in actual building”). The table also lists the drawing scale factor
corresponding to each drawing scale and the common uses for each scale.

Common Architectural Drawing Scales

Drawing scale Drawing scale factor Common Uses
1
/16” = 1’-10” 192 Large building plans
1
/8” = 1’-10” 96 Building plans
¼” = 1’-10” 48 House plan
½” = 1’-10” 24 Plan details
1” = 1’-10” 12 Details
1:200 200 Large building plans
1:100 100 Building plans
1:50 50 House plan
1:20 20 Plan details
1:10 10 Details

Thinking about Paper

With you knowledge of industry’s common drawing scales, you can choose
provisional scale based on what you are depicting. But you won’t know for
sure whether that scale works until you compare it with the size of paper that
you want use for plotting your drawing. Here again, most industries use a
small range of standard sheet sizes. Three common set of sizes exist as
shown below:

 ANSI (American National Standards Institute)

 Architectural
 ISO (International Standard Organization)

Common Plot Sheets

Sheet Size Dimensions Comment
ANSI E 34 x 44”
ANSI D 22 x 34” E sheet folded in half
ANSI C 17 x 22” D sheet folded in half
ANSI B 11 x 17” C sheet folded in half
ANSI A 8 ½ x 11” B sheet folded in half
Architectural large E 36 x 48”
Architectural E 30 x 42”
Architectural D 24 x 36”
Architectural C 18 x 24”
Architectural B 12 x 18”
Architectural A 9 x 12”
ISO A0 841 x 1189 mm
ISO A1 594 x 841 mm A0 sheet folded in half
ISO A2 420 x 594 mm A1 sheet folded in half
ISO A3 297 x 420 mm A2 sheet folded in half
ISO A4 210 x 297 mm A3 sheet folded in half

Setting up drawing area equivalent to Paper size

Procedure:
1. Click on Format menu > Drawing Limits
2. Specify the coordinates for the lower left corner (0,0) and press Enter
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 3. Specify the coordinates for the upper right corner (29700,21000) – for
A4 paper landscape

Drawing the boarder around the drawing area

Draw the boarder around the drawing area by using the drawing limits above
as follows:

Procedure:
1. Click on Draw menu > Rectangle
2. Specify the coordinates for the first corner and press enter
3. Specify the coordinates for the second corner and press enter

Accessing AutoCAD Commands

In AutoCAD commands can be obtained in the three different regions:

Menus: by choosing from the pull-down menu

Toolbars: such as drawing tools, Modifying tools, Properties tools etc

Command line: by typing the required command in the recognised syntax

Drawing Aids (Drafting Settings)

AutoCAD provides tracking and object snap tools to help you draw quickly
and accurately. By using these tools, you can draw precisely without having
to enter coordinates or perform tedious calculations.

To set the required object snaps, right click on the OSNAP in the status bar
and choose settings:

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2. Drawing with AutoCAD

Freehand method

This is a method used to experience sketching in AutoCAD without the

need of using dimensions. Sketching is useful for creating irregular
boundaries or for tracing with a digitizer.

To sketch and record freehand lines

1. At the Command prompt, enter sketch.

2. At the Record Increment prompt, enter the minimum line
segment length.
3. Click the start point to put the “pen” down.
When you move the pointing device, temporary freehand line
segments of the length you specified are drawn. SKETCH doesn't
accept coordinate input. During the command, freehand lines are
displayed in a different color.
4. Click the endpoint to lift the “pen” up so that you can move the
cursor around the screen without drawing. Click a new start point
to resume drawing from the new cursor position.
5. Enter r at any time to record (save) the line you're drawing in the
database and those already drawn.
If the pen is down, you can continue drawing after recording. If
the pen is up, click to resume drawing. The freehand line starts
from wherever the cursor is when you click.

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 6. Press ENTER to complete the sketch and record all unrecorded
lines.

Coordinates method

You can relocate and rotate the user coordinate system for convenient
coordinate entry, grid display, grid snap, Ortho mode, and other drawing
tools.

Understand the World and User Coordinate Systems

There are two coordinate systems: a fixed system called the world
coordinate system (WCS) and a movable system called the user coordinate
system (UCS). By default, these two systems are coincident in a new
drawing.

Normally in 2D views, the WCS X axis is horizontal and the Y axis is vertical.
The WCS origin is where the X and Y axes intersect (0,0). All objects in a
drawing file are defined by their WCS coordinates. However, it is usually
more convenient to create and edit objects based on the movable UCS.

Work with the User Coordinate System

Virtually all coordinate entry as well as many other tools and operations
reference the current UCS. 2D tools and operations that depend on the
location and orientation of the UCS include the following:

Absolute Coordinates:
Coordinate values measured from a coordinate system's origin point (0,0).

Relative Coordinates
Relative coordinates are based on the last point entered. Use relative
coordinates when you know the location of a point in relation to the
previous point.

To specify relative coordinates, precede the coordinate values with an @

sign. For example, entering @3,4 specifies a point 3 units along the X axis
and 4 units along the Y axis from the last point specified.

Polar Coordinates
You can use absolute or relative polar coordinates (distance and angle) to
locate points when creating objects.

To use polar coordinates to specify a point, enter a distance and an angle

separated by an angle bracket (<).

By default, angles increase in the counter-clockwise direction and

decrease in the clockwise direction. To specify a clockwise direction, enter
a negative value for the angle. For example, entering 1<315 locates the
same point as entering 1<-45.

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Practice

Drawing with absolute coordinates

Plot the following coordinates:

Point Coordinate Point Coordinate

s s
1 500,500 6 2500,1000
2 500,1000 7 3000,1000
3 1000,1000 8 3000,500
4 1000,2000 9 C
5 2500,2000 10

Outcome: The figure for the plot will be as shown below:

Drawing with Relative coordinates

Plot the following coordinates:

Point Coordinate Point Coordinate

s s
1 500,500 6 @0,-1000
2 @0,500 7 @500,0
3 @500,0 8 @0,-500
4 @0,1000 9 @-2500,0
5 @1500,0 10

Outcome: The figure should look as shown below:

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 Drawing with Relative Polar coordinates
Plot the following coordinates:

Point Coordinate Point Coordinate

s s
1 500,500 6 @1000<2
70
2 @500<90 7 @500<0
3 @500<0 8 @500<27
0
4 @1000<9 9 @2500<1
0 80
5 @1500<0 10

Outcome: The figure should look as shown below:

Direct Distance

You can specify a point by moving the cursor to indicate a direction and
then entering the distance.

To specify a line length quickly, without entering coordinate values, you can
specify a point by moving the cursor to indicate a direction and then
entering the distance from the first point.

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You can use direct distance entry to specify points for all commands
requiring more than one point. When Ortho mode or polar tracking is on,
this method is an efficient way to draw lines of specified length and
direction, and to move or copy objects

Figure below is an example of direct distance with horizontal from left

to right and vertical line 50 units long. The system is like Polar
coordinates in order to prove that the measured distance is correct
and the line is straight (90).

Practice

Use the information in the table below to draw line segments with given
length and direction:

Distanc Direction Distanc Direction

e e
Start 500,500 1000 Down
500 Up 500 Right
500 Right 500 Down
1000 Up 2500 Left
1500 Right

Outcome: The figure should look as shown below:

Drawing Basic shapes

Rectangle: To draw rectangle:

1. Click on the Draw > Rectangle

2. Specify the first corner by clicking and then drag diagonally
and then click on the opposite corner or
1. Click on the Draw > Rectangle
2. Specify the coordinates for the first corner e.g. 0,0 and press
Enter
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 3. Specify the coordinates for the second corner e.g. 30,20

Practice: draw the rectangle with the following coordinates

 First corner 50,50
 Second corner 250,150

Circle: To draw a circle:

1. Click on the Draw > Circle followed with on of the following
options:

2. Click on the screen to mark the centre and click on another

location to mark the radius or the diameter

Practice: draw the circle with the following coordinates

 center 50,50
 radius 50

Arc: To draw an arc:

1. Click on the Draw > Arc followed with one of the following
options:

2. Click on the screen to mark Start, Center, End or Start,

Center, Angle etc.

Practice: draw the arc with the following specifications

 Center 50,50
 Start 0,100
 Angle 90

Polygon: To draw a polygon:

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 1. Click on Draw > Polygon
2. Enter the number of sides
3. Specify the center of the of the polygon
4. Enter an option (Inscribe in circle or circumscribed about
circle)

5. Specify the radius e.g. 200

Practice: draw the polygon with the following specifications

 Number of sides 6
 Center 100,100
 Option Inscribe
 Radius 100
Challenge:

Geometric Construction

Draw the following objects

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14
3. Editing the Drawing

Basic Editing Commands

Copy Command:

Concept: To create duplicates of objects at a specified distance and

direction from the originals

Procedures:

To copy an object using two points

1. Click Modify menu > Copy.
2. Select the objects to copy.
3. Specify the base point.
4. Specify the second point. Press ENTER

Move Command

Concept: To move objects at a specified distance and direction from the

originals

Procedures:

To move an object using two points

1. Click Modify menu > Move.

2. Select the objects to move.
3. Specify a base point for the move.
4. Specify a second point.
The objects you selected are moved to a new location determined by
the distance and direction between the first and second points

Erase Command

Concept: To remove object from the drawing. You can erase objects from
your drawing using several methods.

 Erase them with ERASE.

 Select them and then cut them to the Clipboard with CTRL+X.
 Select them and press DELETE

Procedures:

To erase an object
1. Click Modify menu > Erase.
2. At the Select Objects prompt, use a selection method to select the
objects to be erased or enter an option:
 Enter L (Last) to erase the last object drawn.
 Enter p (Previous) to erase the last selection set.
 Enter all to erase all objects from the drawing.
 Enter question mark (?) to see a list of all selection methods.
3. Press ENTER to end the command

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Scale Command

Concept: To enlarge or reduce selected objects proportionally in the X, Y,

and Z directions. You can resize objects to make them longer or shorter in
only one direction or to make them proportionally larger or smaller.
You can also stretch certain objects by moving an endpoint, vertex, or
control point.

Procedures

To scale an object by a scale factor

1. Click Modify menu > Scale.
2. Select the object to scale.
3. Specify the base point.
4. Enter the scale factor or drag and click to specify a new scale .

To stretch an object
1. Click Modify menu > Stretch.
2. Select the object using a crossing window selection.
The crossing window must include at least one vertex or endpoint.
3. Do one of the following:
 Enter the displacement in the form of a relative Cartesian,
polar, cylindrical, or spherical coordinate. Do not include the
@ sign, because a relative coordinate is assumed. Press
ENTER at the prompt for the second point of displacement.
 Specify the base point for the stretch, and then specify a
second point, to determine the distance and direction.

Any objects with at least one vertex or endpoint included within the
crossing window are stretched. Any objects that are completely
within the crossing window, or selected individually, are moved
without stretching.

To scale an object by reference

1. Click Modify menu > Scale.
2. Select the object to scale.
3. Select the base point.
4. Enter r (Reference).
5. Select the first and second reference points, or enter a value for the
reference length.

Explode Command

Concept: Breaks a compound object into its component objects. If you

need to modify one or more objects within a block separately, you can
disassemble, or explode, the block reference into its component objects.
After making the changes
Procedures

To explode a block reference

1. On the Modify menu, click Explode.

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 2. Select the block to explode and press ENTER.
The block reference is disassembled into its component objects;
however, the block definition still exists in the drawing for insertion
later

Chamfer Command

Concept: To connect two objects with an angled line. It is usually used to

represent a beveled edge on a corner.

Procedures:

To set chamfer distances

1. Click Modify menu > Chamfer.
2. Enter d (Distances).
3. Enter the first chamfer distance.
4. Enter the second chamfer distance.
5. Select the lines for chamfering

Fillet Command

Concept: To connect two objects with an arc that is tangent to the objects
and has a specified radius.

Procedures:

To set the fillet radius

1. Click Modify menu > Fillet.
2. Enter r (Radius).
3. Enter the fillet radius
4. Select the objects to fillet.

Offset Command

Concept: To create a new object whose shape parallels the shape of a

selected object

Procedures:

To offset an object by specifying a distance

1. Click Modify menu » Offset.
2. Specify the offset distance.
You can enter a value or use the pointing device.
3. Select the object to offset.
4. Specify a point on the side where you want to place the new objects.
5. Select another object to offset, or press ENTER to end the command

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 Trim Command

Concept: To shorten or lengthen objects to meet the edges of other

objects.

Procedures:

To trim an object
1. Click Modify menu > Trim.
2. Select the objects to serve as cutting edges.
To select all displayed objects as potential cutting edges, press ENTER
without selecting any objects.
3. Select the objects to trim.

To extend an object
1. Click Modify menu > Extend.
2. Select the objects to serve as boundary edges.
To select all displayed objects as potential boundary edges, press
ENTER without selecting any objects.
3. Select the objects to extend

Hatching Areas

Hatching fills a specified area in a drawing with a pattern. You can hatch an enclosed
area or a specified boundary using the BHATCH and HATCH commands.

BHATCH creates associative or non-associative hatches. Associative hatches are

linked to their boundaries and are updated when the boundaries are modified. Non-
associative hatches are independent of their boundaries. BHATCH defines boundaries
automatically when you specify a point within the area to be hatched. Any whole or
partial objects that are not part of the boundary are ignored and do not affect the
hatch. The boundary can have overhanging edges and islands (enclosed areas within
the hatch area) that you choose to hatch or leave unhatched. You can also define a
boundary by selecting objects.

To hatch an enclosed area

1 From the Draw menu, choose Hatch.
2 In the Boundary Hatch dialog box, choose Pick Points.
3 Specify a point in your drawing inside each area you want to hatch. If you make a
mistake, you can right-click and choose Clear All or Undo Last Select/Pick from
the shortcut menu.
4 To preview the hatch, right-click and choose Preview.
5 Press ENTER to return to the Boundary Hatch dialog box.
6 Choose OK to apply the hatch.

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To hatch selected objects
1 From the Draw menu, choose Hatch.
2 In the Boundary Hatch dialog box, choose Select Objects.
3 Select the object or objects you want to hatch.

The objects need not form a closed boundary. You can also specify any islands by
selecting objects within other selected objects. If you make a mistake, you can right-
click and choose Clear All or Undo Last Select/Pick from the shortcut menu.

4 To preview the hatch, right-click and choose Preview.

5 Press ENTER to return to the Boundary Hatch dialog box.
6 Choose OK to apply the hatch.

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 Creating Multiple Entities with Array

You can create copies of objects in a rectangular or polar (circular) pattern

called an array. For rectangular arrays, you control the number of rows
and columns and the distance between each. For polar arrays, you control
the number of copies of the object and whether the copies are rotated. To
create many regularly spaced objects, arraying is faster than copying.

Creating Rectangular array

A rectangular array is built along a baseline defined by the current snap
rotation angle. Required information to create the rectangular array are:

1. Number of Columns
2. Number of rows
3. Distance between columns (Column offset)
4. Distance between rows (row offset)

Procedures:

To create a rectangular array

1. Click Modify menu > Array.
2. In the Array dialog box, select Rectangular Array.

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 1 2

3 4

5
6

3. Click Select Objects.

The Array dialog box closes. You are prompted for object selection.
4. Select the objects to be arrayed and press ENTER.
5. In the Rows and Columns boxes, enter the number of rows and
columns in the array.
6. Specify the horizontal and vertical spacing (offsets) between objects
by using one of the following methods:
 In the Row Offset and Column Offset boxes, enter the distance
between rows and between columns. Adding a plus sign (+) or a
minus sign (-) determines direction.
 Click the Pick Both Offsets button to use the pointing device to
specify the diagonal corners of a cell in the array. The cell
determines the vertical and horizontal spacing of the rows and
columns.
 Click the Pick Row Offset or Pick Column Offset button to use the
pointing device to specify the horizontal and vertical spacing.
The example box displays the result.
7. To change the rotation angle of the array, enter the new angle next
to Angle of Array.
8. The default angle 0 direction setting can also be changed in UNITS.
9. Click OK to create the array.

Challenge:

Create the following arrays with the given specifications:

Rectangular array:
Number of Rows: - 2
Number of columns: - 4
Row offset: - 1300
Column offset: - 450
Table size: - 2000 x 1000
Fillet radius around the table: 100
Size of chair: - 200 x 100
Fillet radius around the chair: 10
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Chair Table Rectangular array

Creating Polar Array

When you create a polar array, the array is drawn counter clockwise or
clockwise, depending on whether you enter a positive or a negative value
for the angle to fill.

The radius of the array is determined by the distance from the specified
center point to a reference or base point on the last selected object. You
can use the default reference point (usually an arbitrary point that
coincides with a snap point), or you can specify a new base point to be
used as the reference point

Procedures:

To create a polar array

1. Click Modify menu > Array.
2. In the Array dialog box, select Polar Array.

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3. Next to Center Point, do one of the following:
 Enter an X value and a Y value for the center point of the polar
array.
 Click the Pick Center Point button. The Array dialog box closes
and you are prompted for object selection. Use the pointing
device to specify the center point of the polar array.
4. Click Select Objects.
The Array dialog box closes and you are prompted for object
selection.
5. Select the objects to be arrayed.
6. In the Method box, select one of the following methods:
 Total Number of Items & Angle to Fill
 Total Number of Items & Angle Between Items
 Angle to Fill & Angle Between Items
7. Enter the number of items (including the original object), if available.
8. Use one of the following methods:
 Enter the angle to fill and angle between items, if available.
Angle to Fill specifies the distance to fill around the
circumference of the array. Angle Between Items specifies the
distance between each item.
 Click the Pick Angle to Fill button and the Pick Angle Between
Items button. Use the pointing device to specify the angle to fill
and the angle between items.
 The example box displays the result.
9. You can set any of the following options:
 To rotate the objects as they are arrayed, select Rotate Items As
Copied. The example area displays the result.
 To specify the X,Y base point, select More, clear the Set to
Object's Default option and enter values in the X and Y boxes, or
click the Pick Base Point button and use the pointing device to
specify the point.
10.Click OK to create the array.

Challenge

Create polar array with the specifications given below:

Number of items: - 6
Radius of the Table: - 600
Angle to fill: - 360
Size of the chair: - 200 x 100
Chair position from the circumference of the table 150mm

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 Polar array
Obtaining Information about the Drawing

To calculate a distance
1 From the Tools menu, choose Inquiry > Distance.
2 Specify the first and second points of the distance you want to
calculate.
AutoCAD displays a brief report.

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 Calculating Areas

To calculate an area you define

1 From the Tools menu, choose Inquiry > Area.
2 Select points in a sequence that defines the perimeter of the area to
be measured. Then press ENTER.

AutoCAD connects the first and last points to form a closed area and
displays the area and perimeter measurements.

To calculate the area of an object

1 From the Tools menu, choose Inquiry > Area.
2 Enter o (Object).
3 Select an object.

AutoCAD displays the area and perimeter.

4. Organising and Managing Drawing

Using the Design Center

With DesignCenter, you can manage block references, xrefs, and other
content such as layer definitions, layouts, and text styles

Overview of Design Center

With DesignCenter, you can organize access to drawings, blocks, hatches,

and other drawing content. You can drag content from any source drawing
to your current drawing.

You can drag drawings, blocks, and hatches to a tool palette. Source
drawings can be on your computer, on a network location, or a on website.

In addition, if you have multiple drawings open, you can use DesignCenter
to streamline your drawing process by copying and pasting other content,
such as layer definitions, layouts, and text styles between drawings.

Accessing Named Components

With DesignCenter, you can:

 Browse for drawing content such as drawings or symbol libraries on

your computer, on a networked drive, and on a web page
 View definition tables for named objects such as blocks and layers
in any drawing file and then insert, attach, or copy and paste the
definitions into the current drawing
 Update (redefine) a block definition
 Create shortcuts to drawings, folders, and Internet locations that
you access frequently
 Add content such as xrefs, blocks, and hatches to a drawing
 Open drawing files in a new window
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  Drag drawings, blocks, and hatches to a tool palette for convenient
access

Understand Design Center Window

You can control the size, location, and appearance of DesignCenter.

The Organization of the DesignCenter Window

The DesignCenter window is divided into the tree view on the left side and
the content area on the right side. Use the tree view to browse sources of
content and to display content in the content area. Use the content area
to add items to a drawing or to a tool palette.

Undocked, the DesignCenter window is displayed as shown.

Below the content area, you can also display a preview or a description of
a selected drawing, block, hatch pattern, or xref. A toolbar at the top of
the window provides several options and operations.

Control the Size, Location, and Appearance of DesignCenter

You can control the size, location, and appearance of DesignCenter. Many
of these options can be set by right-clicking and selecting an option on the
shortcut menu.

Attaching External Reference

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 Concepts: Manages and inserts content such as blocks, xrefs, and hatch patterns,
attaches a drawing as an external reference (xref). If you attach a drawing that itself
contains an attached xref, the attached xref appears in the current drawing. Like
blocks, attached xrefs can be nested. If another person is currently editing the xref, the
drawing attached is based on the most recently saved version.

Creating and Inserting Blocks

You create blocks by associating objects and giving them a name. You can also attach
information (attributes) to a block.

You create blocks by associating objects and giving them a name. You can also attach
information (attributes) to a block.

1. How Blocks Are Stored and Referenced

Every drawing file has an invisible data area called the block definition table. The block
definition table stores all block definitions, which consist of all information associated with
the block. It is these block definitions that are referenced when you insert blocks in your
drawing. The following illustrations are conceptual representations of three drawing files.
Each rectangle represents a separate drawing file and is divided into two parts: the smaller
part represents the block definition table, and the larger part represents the objects in a
drawing.

When you insert a block, you are inserting a block reference. The information is not simply
copied from the block definition to the drawing area. Instead, a link is established between
the block reference and the block definition. Therefore, if the block definition is changed, all
references are updated automatically.

To reduce the size of a drawing, you can purge unused block definitions.

2. Create Blocks Within a Drawing

After you define a block in a drawing, you can insert a block reference in the drawing as
many times as necessary. Use this method to create blocks quickly.
Each block definition includes a block name, one or more objects, the coordinate values of
the base point to be used for inserting the block, and any associated attribute data.

The base point is used as a reference for positioning the block when you insert it. Suppose
you specify that the base point is at the lower-left corner of an object in the block. Later,

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when you insert the block, you are prompted for an insertion point. The block base point is
aligned at the insertion point you specified.

The block definition in the illustration comprises a name, PLUG_VALVE, four lines, and a
base point at the intersection of the two diagonal lines.

The illustration shows a typical sequence for creating a block definition within a drawing.

You can also use the Block Editor to create blocks that are saved within a drawing.

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Tutorial:

3. Draw the object you want to make it as a block

4. Click on Draw menu and choose Block and then make. The dialog box shown below will
be displayed.

5. Type in the name of the block and click on Select objects button
6. Select the object you want to make it a block and press enter key
7. Click on Pick point button and then mark any point in the object (to be made as a block)
which will be used as a holding point.

Exercise:

Draw a door swing and window as shown below and convert them to blocks called D1 and
W1 respectively.

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Annotations

Dimensioning Concepts

Design is often divided into four phases: drawing, annotating, viewing, and plotting.
During annotation, the designer adds text, numbers, and other symbols to
communicate such information as the size and materials of design elements or notes
for constructing the design. Dimensions are a common drawing annotation; they show
object measurements such as a wall length, cylinder diameter, or building site area.

AutoCAD provides many dimension types and many ways to format them. You can
specify measurements for all drawing objects and shapes. You can measure vertical
and horizontal distances, angles, diameters, and radii. You can create a series of
dimensions measured from a common baseline or create a series of dimensions
measured incrementally. The following illustration shows examples of dimensions
you can create.

Dimensioning Elements

Although dimensions may vary in type and appearance, most dimensions include
dimension text, dimension lines, extension lines, and arrowheads.

Dimension Text

Dimension text indicates the actual measurement. You can use the measurement
computed automatically by AutoCAD, supply your own text, or suppress the text
entirely. If you use the generated text, you can append plus/minus tolerances, prefixes,
and suffixes.
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Dimension Lines

Dimension line indicates the extent of a dimension. Dimension lines usually have
arrowheads at the end to indicate the dimension start points and endpoints. The
dimension text is placed along the dimension line, which is often divided into two
lines. AutoCAD usually places dimension lines inside the measured area. If space is
not sufficient, AutoCAD may move the dimension lines or text outside the measured
area, depending on the placement rules set for the dimension style (see "Fitting
Dimension Text and Arrowheads"). For angular dimensions, the dimension line is an
arc.

Arrowheads

Displayed at the end of dimension lines to indicate where the measurement begins and
ends. AutoCAD uses the closed filled arrowhead symbol by default. However,
AutoCAD provides many other symbols that you can use, including architectural
ticks, oblique strokes, dots, and slashes. You can also create your own symbols.

Extension Lines

Extend from the dimensioned object to the dimension line. Extension lines are drawn
perpendicular to the dimension line, though you can make them oblique.

Centre Mark

Centre mark marks the centre of a circle or arc. Centrelines extend from the centre
mark. You can use a centre mark only, or a centre mark and centrelines.

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Creating Dimensions

AutoCAD provides 11 dimensions that you can use to measure design objects. To
start a dimension, you can use the Dimension menu or toolbar or enter a dimension
command on the command line. To display the Dimension toolbar, right-click the
Standard toolbar and choose Dimensions.

The following table lists the AutoCAD dimensions and common methods for starting
dimensions. As you create dimensions, you probably will use more than one method,
based on your experience, personal preference, or design tasks.

Using Dimension Styles

Create and apply dimension styles to control dimension appearance variable settings
that control things like arrowhead size, text placement and extension line visibility.

When you want to create dimensions that look like those specified in a given
dimension style, simply make the dimension style current before you create
dimensions. Applying a different dimension style to existing dimensions will change
their appearance.

Entering a name for Dimension Style

1. Click on the Format menu and choose Dimension Style

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2. In the Dimension style manager dialog box, click New
3. At the Style name, type New –ISO-25
4. Click Continue to exit this dialog box

Specifying Lines and Arrows

From the dimension Style dialog box click on Lines and Arrows Tab and set the
required parameters for:

 Colour
 Line weight
 Extend beyond ticks
 Baseline
 Suppression of dimension lines
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Specifying text position and Style
1 Click the Text tab
2 Under Text Appearance, specify Text Style, Colour and Height
3 Under Text Placement, specify Vertical, Horizontal and Offset from the
Dimension line
4 Under Text Alignment, choose the option you want.

Text Height:

In selecting text height, think about the likely scale to be used when plotting the
drawings. For example, if the drawing drawn in millimetres units is to be plotted at a
scale of 1:200, you can set text height to be 1000, that is when plotted text will end up
being 5mm high on drawing (that is 1000/200).

Layers

Layers are like transparent overlays on which you organize and group different kinds
of drawing information. The objects you create have common properties including
colours, line types, and lineweights. An object can assume these properties from the
layer it is drawn on, or properties can be specifically assigned to individual objects.
Colour helps you distinguish similar elements in your drawings, while line types help
you differentiate easily between different drafting elements, such as centrelines or
hidden lines. Lineweights represent the size or type of an object through width,
enhancing your drawing and increasing legibility. Organizing layers and the objects
on layers makes it easier to manage the information in your drawings.

To create a new layer

Procedures

1 From the Format menu, choose Layer.

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2 In the Layer Properties Manager, click on New button (before red X).

A new layer is displayed in the list with the temporary name LAYER1.

3 Enter a new name.

4 To create more than one layer, choose New again, enter the new layer name, and
press ENTER.
5 Choose OK.

Plotting

To Create a Layout to Plot

1 Before you begin creating a layout to plot, specify the plotting device. To add a
new plotter configuration, choose Plotter Manager from the File menu.
2 Choose the layout tab you want to plot.
3 From the File menu, choose Page Set up (if the Page Set up dialog box isn't
already displayed).
4 In the Page Set up dialog box on the Layout Settings tab, specify the paper size,
paper units, and drawing orientation.

If the PAPERUPDATE system variable is set to 1, you are prompted if the

layout's existing paper size is not supported by the plotting device you have
selected. The paper size is automatically updated to reflect the default paper size
of the selected plotting device.

5 Under Plot Area, select the area you want to plot. The default setting is Layout for
the layout tab and Display for the Model tab.

To define an area in the layout to plot, select Window, and then choose the
Window button to the right. Use your pointing device to define the boundary of
the area in the drawing you want to plot.

6 Under Plot Scale, either select from the list of standard scales, or enter a custom
scale. If you select a standard scale, that scale is displayed at Custom.

The default scale setting for a layout is 1:1. The default scale setting for a model
is scaled to Fit.

7 To scale line weights proportionately with the plot scale, select Scale Line
weights.

Typically, the plot scale is 1:1. However, if you plot at half scale, the plot scale
would be 1:2, and the line weight would be scaled proportionately.

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8 Under Plot Offset, enter the X and Y offset values to specify an offset from the
lower-left corner of the printable area. The values you enter are calculated
automatically to centre the plot.

9 Under Plot Options, select or clear Plot with Line weights to control whether line
weights are plotted.

10 Select Plot with Plot Styles to include the plot style properties assigned to the
layout or view port.

11 Choose OK.

Creating and Editing Viewports in a Layout

To see model geometry in a layout, create floating viewports. A floating viewport
resembles a glass window you open to view model space geometry from within a
paper space layout. Specify a view, scale factor, plot style table, and visible layers for
each floating viewport in a layout.

Double-click in a floating viewport to edit the model space objects it shows. Double-
click in the area around floating viewports to modify your layout. Click the Model tab
to hide the layout altogether. In this lesson you will create and edit Rectangular
floating viewports in a layout.

Creating Rectangular Viewports

1. Click on the Layout1 tab and click cancel to close the Layout1 window (if it
appears)
2. On the View menu click Viewports then click 1 Viewport.
3. Drag the mouse to create the viewport to the size you want or type in the
coordinates to represent the size of the viewport you want.

Single viewport

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4. Double-click inside the floating viewport to switch from paper space layout to
work in the floating viewport.

Viewport after double clicking on it

5. On the Standard toolbar, click Zoom Window.

6. Click two points to put a window around the floor plan.
7. Double-click in the edge area around the viewport to work on paper space layout.
8. Click the edge of the floating viewport to display its grips.

9. On the Modify menu, click Properties.

10. In the Properties window, click
Standard Scale and select the
scale you want to apply to the viewport.
11. Click Display Locked and select
Yes to lock the set viewport scale to
zoom in to different areas of detail. It
will not change the viewport scale.

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 Viewport scale set to 1:100 and locked set to Yes

12. Close the Properties dialog box.

13. Press ESC twice to remove grips.
Controlling Layers Display in Layout
When you work with multiview drawings, determine which objects are visible in the
view using layers. Freeze or thaw layers in any viewport using either the Layer list on
the Object Properties Toolbar or the Layer Properties Manager dialog box.
In this lesson you will learn how to hide layers in floating viewports and Controlling
the Visibility of Layers in New Viewports

Hiding Layers in Floating Viewports

1. Double-click the viewport (into which you want to hide layers) to make it active.
2. On the Object Properties toolbar, click Layers.
3. In the Layer Properties Manager dialog box, click Show Details.
4. Hold down the CTRL key and select the layers you want to freeze within the
active viewport
5. Under Details, click Freeze in Active Viewport to freeze layers in the current
view, and then click OK to exit this dialog box.

Controlling the Visibility of Layers in New Viewports

1. On the Object Properties toolbar, click Layers.
2. Hold down the CTRL key. In the Layer list, under Name, click the layers you
want to control its display
3. Under Details click Freeze in New Viewports. This ensures that these layers will
remain hidden in all future viewports.
4. Click OK to exit this dialog box.

Creating Viewport using New Viewports command

You can also create Viewports by using New Viewports command available in the
View menu. To create New Viewports using New Viewports command:
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1. Click on View menu and choose New Viewports…
2. Click New viewports tab
3. Select the type of viewports you want to create from Standard Viewports list
provided
4. Specify Apply to and or specify View spacing and set up

New Viewports in 3D Set up

Two viewports one to a scale of 1:2 and 1:4

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Viewport in 2D set up Viewport in 3D set up

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