Introduction to AutoCAD

Source: ENGT 122 – CAD I

Computer Aided Design
(Assoc.Prof.Dr. Ahmet Zafer Şenalp)
What do you think CAD is?
Basic Definitions

CAD: Computer Aided Design

is the use of computer technology for the process of design and design-
documentation.
CAM: Computer Aided Manufacturing
Production operations planning, management and control, directly or
indirectly brought face to face with the computer systems technology

CAE: Computer Aided Engineering

CAD geometry is analyzed using computer systems, by giving designers

the opportunity to work on product design and simulation to improve
and optimize the design.
 Broad Applications
• Mechanical Design and Visualization
– Detailed Design and Electronic Drafting
– Parametric Modeling

• Motion Simulation/Animation

• Engineering Analysis and Optimization

– Pre- and Post- Graphical Processors for Finite Element Analysis
(Mechanics, Dynamics, Thermo-flow, etc.)
– Identification of Optimal Design Parameters and Configurations
– Motion Analysis (Location, Speed, Acceleration and Force)

• Manufacturing Planning of Simulation

– Machining
– Industrial Robots
Applications in Mechanical Designs
What is CAD?

 CAD stands for Computer-Aided Design/Drafting.

 It involves inputting lines, arcs, dimensions, and text into an

electronic database for engineering purposes and in
compliance with specific industry standards.

 The ability to manipulate graphical data in many ways during

and after completion of any job.
 What is AutoCAD?
 AutoCAD is an interactive general purpose CAD (Computer
Aided Drafting) program.

 Developed in California in the early 1980’s by Autodesk Inc.

 Used in many disciplines: mechanical, civil, architectural,

electrical, etc.

 Performs 2D drafting, 3D surfaces, and 3D solid modeling.

 Functionality is extremely comprehensive to suit various needs.

Difficulty ranges from very easy to very complex, depending on
user requirements.
What do you think are the advantages of
CAD over Mechanical Drafting?
 CAD Advantages
 CAD software is more accurate.
 Lines are crisp and clean.
 Text is legible (usually).
 Erasures are undetectable.
 More productive.
 Repetitive operations can be performed with a single command.
 Symmetrical parts are easily replicated.
 Editing drawings is much easier.
 Drawing can be transferred electronically.
 Storage requirements are minimal.
 Drawing retrieval process is much easier.
 Data is reusable.
General Company Structure
 AutoCAD
Starting AutoCAD Icon

3 ways to start AutoCAD:

 Double-Click AutoCAD 2012
English icon on your desktop.

 Use the Start Menu –

Start > All Programs >
Autodesk > AutoCAD 2012-
English > AutoCAD 2012-
English

 Double-Click an AutoCAD .dwg

file in Windows Explorer.
 Start AutoCAD
 Uncheck the Show this window at start up check box and close the
AutoCAD Exchange window.

Uncheck Close
 Switch the Status Bar from icons to text (right click on any status bar
button and uncheck Use Icons)
 Toggle off all Status Bar buttons (should turn gray, not blue)

Status Bar
 Type the command STARTUP at the command prompt and
then press the Enter key.
 Enter a value of 2 and then press the Enter key.
Shutting Down AutoCAD

To Exit AutoCAD

 If you intend to keep the drawing data

be sure you SAVE before exiting!
 Exiting AutoCAD:
 From Application Menu
 Or click  in upper right corner.
 Or type EXIT at command prompt
followed by [Enter].

To Exit AutoCAD
 Starting a New File
 You can start a new file using the
Application Menu > New or the New
button on the Quick Access Toolbar.

English units (feet, inch)

Metric units (mm)

 To work in English units (feet
or inches) choose acad.dwt
from Select Template dialog
box.
 To work in Metric units (millimeters) choose acadiso.dwt from Select
Template dialog box.
 Startup - Using a Template
 AutoCAD drawings are identified by a .dwg extension. When you save
a drawing a .dwg extension is applied.

 However, when you start a new drawing, AutoCAD loads a template

file with a .dwt extension.

 So What is a Template?
Standardized file formats with preset
internal variables. Provided by AutoCAD
or created by user.
 Limits (drawing length & width)

 Text Height

 Dimension Scale

 Linetype Scale
 Startup - Using a Template
 You can start a drawing using a standard AutoCAD template or a user
defined template that you create.Your Drawing settings will match the
defined template properties.
 AutoCAD Templates:
 Standardized formats provided with
AutoCAD.
 Typically found in AutoCAD
subfolder called Templates.
 User defined templates:

 Template file containing commonly

used settings & objects.
 Use Browser to locate user template.
 Startup – Using a Template
 Important:You must start with the correct template that
corresponds with the units you intend to use.

 For Imperial/English Units  For Metric Units

 units = millimeters
 units = feet and inches
 Template file = acadiso.dwt
 Template file = acad.dwt
Saving Your Work!
 As you work on an AutoCAD drawing, all
data for the drawing resides in RAM
memory on the computer.

 If you close the AutoCAD session or some

other misfortunate event occurs, ALL DATA
WILL BE LOST! AND CANNOT BE
RECOVERED!
 Saving Your Work!
Top 8 Events that will make you cry!
1. Accidentally exiting AutoCAD.
2. AutoCAD bugs.
3. Failure of Microsoft Windows OS.
4. Power failure (frequent occurrence).
5. Unrecoverable error in drawing.
6. Network issues or shutdown.
7. Disrupting a network or power cable.
8. Missing an assignment due to above!
Saving Your Work!

 Most common ways to Save are the Application

menu commands:
Save & Save As…
 First time file is saved, a file name must be
supplied. Either command brings up “Save As”
dialog box for file name entry.
 Subsequent saves:
 Save – saves to the existing drawing file name. No
prompts or dialog box occurs.
 Save As - brings up same dialog box. If new name
is provided, data is saved to that new file and
current drawing session name is updated.
Opening and Closing Files

 You can open and close multiple files at

any time without leaving AutoCAD.
 Typically use Application menu to
perform such operation.

•Starts a new file. Initiates Select Template dialog box.

•Opens an existing file. Initiates Select-File dialog box.

Allows you to browse for desired file.

•Closes the active session. If the session has not been saved,
a prompt to save will be initiated.
Application Menu
Quick Access Toolbar Ribbon Screen Layout

Toolbar Menus Ribbon Menu

Graphics Window
World CS Origin

Command Window

Status Bar Buttons

 Making AutoCAD Do Stuff
 AutoCAD uses Commands, Command Input Data, and System
Variables in order to perform a particular function.

 Commands – user selected instructions telling AutoCAD which

operation to perform.
 Example: Line – creates a line
 Example: Circle – creates a circle

 Command Input Data – additional input data supplied by the user

when issuing a command.
 Example: End points for creating a line with the Line command

 System Variables – Internal AutoCAD data settings that control how a

particular AutoCAD command is performed.
 Command Input
 Redundant Commands –
 A specific command can typically be issued by various methods.
 Don’t let this confuse you, it simply allows options for you to work in a
manner you prefer.

 Methods for issuing a command:

 Keyboard / Command Line
 Ribbon Menus
 Toolbar Button Menus

 Be Observant - for all methods the Command Window will prompt

for command input data, indicate command status, and list the
command history.
Keyboard / Command Line:
 Type a command at command line prompt Command: followed by
[Enter]
 Command prompt (Command:) must first be displayed, otherwise a
previous command is still active.
 Use [Esc] to cancel previous command.

Command history

Command line prompt or data input prompt

 Arrows indicate additional options or
commands Panel names within Tabs

Ribbon Menu:
 Uses Tabbed categories.
 Within each tab are categorized Panels
 Select command with left mouse button.
 Drop down arrows indicate additional
options/commands.

Command history
data input prompt
 Tool-Tip for Line command

Toolbar Menus:
 Hold mouse pointer over toolbar command to
display tool-tip (name of command).
 Select command icon with left mouse button.
 Only displayed toolbars are accessible and not all
command options are available.

Command history
data input prompt
Toolbar Menus:
 Toolbar commands are grouped in logical categories;
 Draw Toolbar, Modify Toolbar, etc.
 Toolbar menus are configurable;
 Can be displayed or hidden.
 Can be reshaped.
 Can be arranged anywhere on the screen.
 Toolbar visibility is controlled by;
 Right mouse click on any toolbar.
 -TOOLBAR command.

Right click on any toolbar