CHAPTER 1B

INTRODUCTION TO AUTOCAD

PDT176 COMPUTER-AIDED DRAFTING

Introduction

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To start a new drawing

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Selecting a Template

Workspace drop-down menu

In AutoCAD, new drawings are typically created with some

form of template.

Simple drawings can be created with the acad.dwt template.

Select template dialog box 5

EXPLORING THE DRAWING WINDOW

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Grid Lines

Drawing Area

View Cube

User Coordinate

System UCS icon

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INTERACTING WITH THE DRAWING

WINDOW

Page Setup Manager

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Page Setup Manager

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DRAWING UNITS

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AutoCAD can work in any of five different unit systems:

scientific, decimal, engineering, architectural, or

fractional.

Precision of the units system

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Select degree

precision

for angles here. Select two

decimal places.

TABs AND PANELS

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The headings across the top of the screen (Home, Insert,

etc.) are called tabs, and the groupings of commands

under the tabs are called panels.

Panels Tab

EXPLORING COMMAND ENTRY METHODS

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Line tool

Basic tooltip

Extended tooltip

1. Locate the cursor arrow on the selected tool (icon). In the example

shown, the Line command tool within the Draw panel was

selected.

2. Hold the arrow still without pressing any mouse buttons.

Additional Commands within a Panel

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Additional

commands are

available by

clicking the

arrow to the

right of the

panel’s name

GRID AND SNAP

The Grid

command is used

to place a lined grid

background on the

drawing screen

The Snap command

limits the movement

of the cursor to

predefined points on

the screen

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GRID

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Grid : 20 Grid : 5

Snap Mode button on status bar

In AutoCAD 2013, Snap mode will be active only when

you have entered a command that asks you to pick a

point..

TIP

Incremental snap is more than a convenience.

In many cases, it is a necessity. With snap off, it

is virtually impossible to locate any point

precisely with the mouse. If you try to locate

the point (6.5000,6.5000,0.0000) with snap off,

for example, you may get close, but the

probability is very small that you will actually

be able to select that exact point. Try it.

SNAP

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Cartesian and Polar Coordinate System

Cartesian coordinates - xyz (x, y, and z values separated by a

comma) you can use the coordinate display to pick a point in your

drawing while the dynamic display continues to show the polar

coordinates of the line you are drawing.

Polar Coordinates - (length<angle, z) The two dimensions in the

dynamic input display will show a visual display of polar coordinates.

Polar coordinates are given as a length and an angle relative to a

starting point.

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Working With Coordinate Systems

Direct Distance Entry - You can also enter values directly to

the dynamic input display. For example, you can pick the first

point of a line and then show or type the direction of the line

segment you wish to draw, but instead of picking the other

endpoint you type in a value for the length of the line.

Absolute Coordinates and # - It is important to know that you

can also type the absolute coordinates (8,8) at the Specify

second point: prompt, but you must first type the number (#)

sign. The # sign specifies absolute coordinates rather than

coordinates relative to the last point.

Relative Coordinates and @ - Besides typing or picking points

on the screen, AutoCAD allows you to enter points by typing

coordinates relative to the last point selected.

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Ortho Mode

Ortho Mode - Ortho forces the pointing device to pick

up points only along the horizontal and vertical

quadrant lines from a given starting point. With Ortho

on, you can select points at 0°, 90°, 180°, and 270°

of rotation from your starting point only

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Polar Tracking

Polar Tracking - Polar tracking is an AutoCAD feature

that can replace Ortho mode in many instances.

With Polar Tracking on, when the rubber band crosses

a vertical or horizontal axis (i.e., when the rubber band

is at 0°, 90°, 180°, or 270°), a dotted line appears that

extends to the edge of the drawing area.

Notice that Polar Tracking and Ortho are mutually

exclusive. They cannot both be on at the same time.

When you turn Polar Tracking on, Ortho shuts off

automatically.

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Command

Prompt

Window

INTERACTING WITH THE DRAWING

WINDOW

Typed commands and options appear here.

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THE COMMAND LINE BOX

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The command line box is

located at the bottom of

the drawing screen. It can

be used to access

commands that do not

have their own icons, or

to select options

associated with the

command.

The word CIRCLE will

automatically appear in

the command box when

the Circle command is

clicked on the Draw

panel.

The new command line has the quality of transparency,

most noticeable when it is moved into the drawing area.

Because it is transparent, it interferes only minimally with

objects behind it.

You will also notice that as commands are typed, the last few

command line prompts and responses (by default, the last three) are

displayed above the Line.

EXPLORING COMMAND ENTRY METHODS

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(Infer Constraints, Snap Mode, Grid Display, Ortho

Mode, Polar Tracking, Object Snap, 3D Object Snap,

Object Snap Tracking, Dynamic UCS, Dynamic Input,

Lineweight, Transparency, Quick Properties, and

Selection Cycling).

INTERACTING WITH THE DRAWING

WINDOW

Below the command window

is the status bar, with the

coordinate display on the

left.

To the right of the coordinate

display are mode buttons.

These are switches for

turning on and off some

extremely important features

of the drawing window.

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EXPLORING COMMAND ENTRY METHODS

Many of the most often used commands, such as LINE,

ERASE, and CIRCLE, have aliases.

List of possibilities

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DYNAMIC INPUT DISPLAY (F12)

Dynamic input display is a very powerful feature that in many ways duplicates the function of the coordinate display.

However, this display is easier to track because it follows your cursor. Also, there are times when it can be used effectively in conjunction with the coordinate display.

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DYNAMIC INPUT DISPLAY

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With the display off, the

dynamic input numbers

on your screen

disappear.

FUNCTION KEYS

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F1: HELP

F2: COMMAND WINDOW ON/OFF

F3: OSNAP ON/OFF

F4: 3DOSNAP ON/OFF

F5: ISOPLANE LEFT/RIGHT/TOP

F6: DYNAMIC UCS ON/OFF (In 3D modeling)

F7: GRID ON/OFF

FUNCTION KEYS

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F8: ORTHO ON/OFF

Useful in creating straight lines vertical or horizontal

F9: SNAP ON/OFF

Snap to grid, restricts movement of cursor to specified

intervals.

F10: POLAR ON/OFF

restricts cursor movement along

specific polar angle.

F11: OTRACK ON/OFF

F12: DYNAMIC INPUT ON/OFF