PDF- -Computer Aided Design (CAD) - MIT OpenCourseWare - Cad 2d Class Presentation

Class Presentation


Auto CAD Level

Session Plan

CAD Versions

Hardware Requirements

Opening AutoCAD Application The AutoCAD Screen Opening a Drawing File

Page Navigation

Pan Closing a Drawing File

Creating a New File Creating a Drawing

Saving a Drawing file

Introduction to CAD Applications CAD as a digital tool for Engineering

Engineering needs many Planning and Implementation Tools

Drafting and Designing are important tools for Engineering

Usually Drafting is done using the Drawing sheets,


Drafters and other Drawing Instruments

With advent of computers the scene has changed

Now Computer Software Applications are used for Drawing and Designing the Engineering Plans

The CAD or CADD The Computer Aided Designing (CAD) or Computer Aided Drafting (CADD) are the terms used for using computers for drawing and designing applications under various platforms

The Mainframe and Super computers use CAD/CADD workstations for creation of Engineering drawings and Designs

The CAD Applications

CAD applications softwares prevalent today are AutoCAD,


Pro-E etc

These applications are manufactured by various companies and are specialised for various areas of drawing and designing

AutoCAD History AutoCAD is the CAD Application Software manufactured by AutoDesk Inc

Version 1

Version 1

Version 1

Version 1

Version 2

Version 2

Version 2

Version 2

Release 9

Release 10

Release 11

Release 12

Release 13

Release 14 AutoCAD 2000 (R15

Benefits of Using AutoCAD Quickly create designs Needs less storage Space Improved quality over hand drafting Can be customized to suit the individual’s needs Drawing modification is very easy Can Draw to the actual scale and can be scaled during printing Helps in preparation of Plan as well as 3 Dimensional Models and helps in product walkthroughs

Hardware Requirements Version 1

Version 1

Version 1

Version 1

Version 2

Version 2

Version 2

Version 2

Release 9

- 8088,

Release 10

- 80286,

Release 11

- 80386,

Release 12

- 80486,

Release 13

- 80486,

Release 14

AutoCAD 2000 (R15

AutoCAD 2000i (R15

AutoCAD 2002 (R15

AutoCAD 2004 (R16

AutoCAD 2005 (R16

AutoCAD 2006 (R16

AutoCAD 2007 (R17

AutoCAD 2008 (R17


AutoCAD 2009 (R17

AutoCAD 2010

Starting AutoCAD Use Start

Or Click the Desktop

Icon on the

The AutoCAD interface will open

AutoCAD 2009 Screen (2D Drafting & Annotation Type)

AutoCAD 2009 (3D Modeling Screen Type)

AutoCAD Classic Screen Mode

Menu Browser

Various Tool Bars with Tool Buttons

Menu Bar

Title Bar

AutoCAD Classic Screen Mode

Cross Hair Mouse Pointer

Drawing Tool Bar

Drawing Area WCS (World Co-ordinate System) Icon

Modification Tool Bar

Model and Layout Page Tabs Command Area and Command Prompt

Settings Buttons

Status Bar

Page Navigation Zooming and Panning in the Drawing

Opening a Drawing File

Use file

Understanding the difference between a Drawing and a Template

Using Zoom Options

Using Pan Options

Saving a Drawing File

Opening a New Drawing Page Use File

Click the New File Button from the Quick Selection Menu

Select the acad

dwt (the autocad default drawing template) file when creating a new drawing file

Making the First Drawing Line Command: Used to create straight line by joining two points

Select the Line Command option from Drawing Tool bar or Drawing Menu Bar or Give Line Command at Command Prompt,

the shortcut command l'can also given

The command area will respond by asking to select the first point of the line: select any point on the drawing screen or provide a co-ordinate point say 0,0

Point Selection Methods Absolute Co-ordinate point selection method

Point is selected by providing the absolute coordinate point : x,y Relative Co-ordinate point selection method

A point is selected as displacement from the previously selected point : @∆ξ,

∆ψ Πολαρ Χο−ορδινατε ποιντ σελεχτιον µετηοδ

Α ποιντ ισ σελεχτεδ βψ προϖιδινγ τηε διστανχε ανδ ανγλε φροµ τηε πρεϖιουσ ποιντ : ≅διστανχε Raster Image Reference Insert

The External References method can also be invoked from : Tools



Scaling an image in the drawing can be done similar to how we do for other drawing objects


Contrast and Fade settings can be done on an Image

Image Insertion Exercise (Inserting an Image)

Region Regions are two-dimensional enclosed areas that have physical properties such as centroids or centers of mass

We can combine existing regions into a single,

complex region to calculate area

Regions are two-dimensional enclosed areas you create from objects that form closed loops

Loops can be combinations of lines,

The objects that make up the loops must

Creating a region out of a Loop & Analysing R4

33° 19

Boundary Regions can also be created using Boundary Command

Application of Boundary is same as that of the region

Both are extensively used in 3 Dimension to create 3 Dimensional Extruded Solid Objects

Wipeout Wipeout objects cover existing objects with a blank area to make room for notes or to mask details

A wipeout object is a polygonal area that masks underlying objects with the current background color

This area is bounded by the wipeout frame,

which you can turn on for editing and turn off for plotting

You can create a wipeout object by specifying a polygonal area with a series of points,

or you can convert a closed polyline into a wipeout object

Revision Cloud Revision clouds are polylines that consist of sequential arcs

They are used to call attention to parts of a drawing during the review stage

If you review or redline drawings,

you can increase your productivity by using the Revision Cloud feature to highlight your markups

REVCLOUD creates a polyline of sequential arcs to form a cloud-shaped object

You can select a style for a revision cloud: Normal or Calligraphy

If you select Calligraphy,

Revision Cloud

Defining Drawing Units : UNITS command Before we start to draw,

we must decide what one drawing unit represents based on what we plan to draw

We can convert a drawing between systems of measurement by scaling it

Every object we create is measured in drawing units

Before we start to draw,

we must decide what one drawing unit will represent based on what we plan to draw

Then we create our drawing at actual size with that convention

For example,

a distance of one drawing unit typically represents one millimeter,

or one foot in real-world units

Convert Drawing Units If we start a drawing in one system of measurement (imperial or metric) and then want to switch to the other system,

use SCALE to scale the model geometry by the appropriate conversion factor to obtain correct distances and dimensions

For example,

to convert a drawing created in inches to centimeters,

you scale the model geometry by a factor of 2

To convert from centimeters to inches,

Layers Layers are used to group information in a drawing by function and to enforce linetype,

Layers are the equivalent of the overlays used in paper-based drafting

Layers are the primary organizational tool used in drawing

We use layers to group information by function and to enforce linetype,

Layers By creating layers,

we can associate similar types of objects by assigning them to the same layer

For example,

we can put construction lines,

and title blocks on separate layers

You can then control the following: ●

Whether objects on a layer are visible or dimmed in any viewports

Whether and how objects are plotted

What color is assigned to all objects on a layer

What default linetype and lineweight are assigned to all objects on a layer Whether objects on a layer can be modified

Exercise for Layer: Put Object and Dimensions in different Layers

62° 26 8

6 19 25 48

Session Plan

Drawing a Building Plan

Applying Layers to Building Plan

Working with Surveyor’s Angles

If we use surveyor's angles when specifying polar coordinates,

indicate whether the surveyor's angles are in the north,

For example,

to enter a coordinate relative to the current coordinate for a property line that is 72 feet,