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# Introduction and Basics of AutoCAD

I am back here with a very basic and most essential post for AutoCAD beginners about basics of AutoCAD. This article is AutoCAD basics book. It is specially tailored for AutoCAD beginners, students, and learners.

The AutoCAD design package is a general purpose computer aided design/drafting appliance for your mainframe.CAD applications are tremendously powerful tools. The pace and ease with which a drawing can be arranged and modified using a computer offers a unique advantage over manual preparations. It brings sophisticated technology, which was previously available only on extensive and costly systems, now on desktop computers.

There is virtually no limit for the types of drawing that can be prepared using AutoCAD. Just a few applications for which CAD is being used today are:

- Architectural drawings
- Interior designs and facility planning.
- Topographic maps.
- Electronic, Chemical, Civil, Automotive & Mechanical Engineering applications.
- Workflow charts and Organizational diagrams.
- Proposals and Presentations.

The applications don’t stop with this when used in conjunction with Autoshade, Autoflix, and AutoLISP; it makes AutoCAD superior to all other CAD packages.

## MINIMUM HARDWARE REQUIREMENTS:-

This piece of writing provides the system requirements for AutoCAD 2019 together with particular Toolsets.

- 2.5–2.9 GHz processor.
- 8 GB RAM.
- 6 GB HDD Space.
- 1 GB GPU with 29 GB/s Bandwidth and DirectX 11 compliant
- Keyboard (101 keys).
- Mouse.

The exact specifications can be found on AutoDesk official website. The above-listed equipment is sufficient for basic AutoCAD installation. With this equipment, you can learn how to use AutoCAD.

## HOW TO START AUTOCAD:-

Two methods can start AutoCAD:

- When you start with Microsoft Windows, double-click on the AutoCAD icon if available on the desktop screen.

Start->Programs->AutoCAD - The front-end screen shown below will appear. This screen divided into parts and each part has its function and purpose.

## Interface of AutoCAD

Before starting it is very important to get an in-depth knowledge of AutoCAD program.

#### PULL DOWN MENUS:-

The set of menus from FILE to HELP is known as Pull Down Menu. We can access commands using these menus. These are divided into some parts, e.g., FILE, EDIT, VIEW, INSERT, etc. and a single menu from this is known as Pop Menu.

#### SCREEN MENU AREA:-

The area where the command menus are located is known as Screen Menu Area from we can access our commands. When we give any command from the top menu, the Screen menu is updated accordingly.

#### TOOLBARS / Ribbon:-

These are small icons, and by clicking on this icon we can access the command. It the cursor is rested on a particular icon for some time, it will give us a tip as for which command the icon is meant.

#### CROSSHAIR CURSOR:-

Until now we have seen a small dashed cursor, now this cursor is changed to cross which is known as Cross Hair Cursor.

#### UCS ICON:-

This is a symbol which represents the X Direction and Y Direction.X-axis is at present at 0 degrees and Y-axis at 90 degree

#### COMMAND AREA:-

We can type our commands here. This is also known as command line or command prompt.

### TYPES OF COMMANDS IN AUTOCAD

If the pointing device has multiple buttons, often used commands can be entered using the extra buttons.

#### REPEAT COMMANDS: –

The previous command is repeated if we press a new enter or a space bar. Such command is known as Repeat Command.

#### TRANSPARENT COMMANDS:-

When one command is in the process, another command is taken in that command by typing an apostrophe (‘) before it. Then the second command becomes an explicit command.

### TYPES OF SYSTEMS IN AutoCAD

The system is broadly classified into two parts:

- FIXED SYSTEM:-

A system which does not change with respect to the paper size and drawing, it known as a fixed system.

- VARIABLE SYSTEM:-

System variables are settings that manage how specific commands work. They can turn on or off modes like Snap, Grid or Ortho. AutoCAD system variables can set default scales for hatch pattern. They can store information about the present drawing and AutoCAD’s configuration. Sometimes you use a system variable to change a setting; sometimes you use a system variable to display the current status. There are 293 system variables out of which some are used in 2D drafting while some are used in 3D construction drawings.

### BASIC AUTOCAD COMMANDS

Here is a list and introduction to basic AutoCAD commands for everyday use.

#### LINE:-

(Creates straight segments)

To draw a line following three methods are used to describe where the point lies. To get a bright idea to let us take an example of the square of 4 by four units and let us see how we can draw the square of the specified dimensions by using three methods.

#### ABSOLUTE CO-ORDINATE METHOD:-

This method is based on Cartesian Coordinates. Here we have to give the X and Y coordinates values of the point in the format x,y. An empty ‘Enter’ at the prompt will terminate the command.

Command: LINE enter

From point: 2,2 enter

To point: 6,2 enter

To point: 6,6 enter

To point : 2,6 enter

To point : 2,2 enter

To point: Enter

#### RELATIVE CO-ORDINATE METHOD:-

This method is based on the displacement of the next “end” of “line segment” from the “last point” drawn in Cartesian Coordinates. To distinguish it from the absolute coordinate method, we will have to give’ @’ symbol that denotes the previous point and the X displacement, Y displacement in the format @x displacement, y displacement.

Command: LINE enter

From point : (pick any point)

To point: @4,0 enter

To point: @0,4 enter

To point: @-4,0 enter

To point: @0,-4 enter

To point: enter

**Refer to this useful tutorial for Drawing Line in Different Units.**

#### POLAR CO-ORDINATE METHOD:-

This method is based on the displacement of the next “end” of “line segment” from the “last point” drawn in Polar Coordinates.

To distinguish it from the Cartesian relative Coordinates method, we will have to give’ <‘ symbol that separates the length of the segment from the angle from start point. The format of this method is @distance

Command: LINE enter

From point : (pick any point)

To point : @4<0 enter

To point: @4<90 enter

To point: @4<180 enter

To point: @4<270 enter

To point: enter

#### ARC:-

(Creates an arc)

There are 11 different ways to draw an arc. The sequence of points picked is as the name of the method.

3point

Start – Center – End

Start – Center – Angle

Start – Center – Length of Chord

Start – End – Included Angle

Start – End – Direction From Start

Start – End – Radius

Center – Start – End

Center – Start – Angle

Center – Start – Length of Chord

#### CIRCLE:-

(Creates a circle)

*3POINT (3P) METHOD:

This method needs 3 points to be specified, and a circle will be generated by joining these 3 points.

Command : CIRCLE enter

3P/2P/TTR/{center point}: 3P enter

First Point : 3,2

Second Point : 5,4

Third Point : 4,5

A circle will be generated joining (3,2),(5,4),an(4,5).

NOTE:- The 3 points should not be collinear.

*2POINT(2P) METHOD:

This method needs 2 points to be specified, and a circle will be generated by joining these 2 points.

Command: CIRCLE enter

3P/2P/TTR/{center point}: 2P enter

First Point on diameter: 4,4 enter

Second Point on diameter: 8,4 enter

A circle will be generated by joining (4,4) and (8,4) which are the endpoints of the diameter.

*TANGENT – TANGENT – RADIUS (TTR) METHOD:

This method used to draw a circle of known radius, tangent to previously drawn any two entities.

Command: CIRCLE enter

3P/2P/TTR/{center point}: 2P enter

Enter tangent spec : (click on p1)

Enter second tangent spec : (click on p2)

Radius : (give the value of R) enter

*CENTER – RADIUS METHOD:

This method used to draw a circle when the center point of a circle and the radius is known(Say center point lying on CP and radius of R)

Command: CIRCLE enter

3P/2P/TTR/{center point}: (click on CP)

Diameter/{Radius}:(give value of R) enter

*CENTER – DIAMETER METHOD:

This method used to draw a circle when the center point of a circle and the diameter is known (Say center point lying on CP and diameter of D)

Command: CIRCLE enter

3P/2P/TTR/{center point}: (click on CP)

Diameter/{Radius} : D enter

Diameter :(give value of D) enter

#### POLYGON:-

(Creates an equilateral closed polygon)

To draw regular polygon POLYGON command is used. A regular polygon with minimum 3 to maximum 1024 sides can be drawn. The size of the polygon can be specified in two ways. You can enter the length of one of the edges or define a circle.

Let us try how we can draw a 6-sided polygon inscribed in and Circumscribe about a circle whose center point lying on CP and radius R.

Command: POLYGON enter

Number sides: 5 enter

Edge/{Center of polygon} : (click on CP)

Inscribed in circle/Circumscribed about the circle(I/C) : I enter

The radius of circle : ( give the value of R) enter

This will generate a polygon inscribed in a circle.

Command: POLYGON enter

Number sides: 5 enter

Edge/ {Center of polygon} : (click on CP)

Inscribed in circle/Circumscribed about the circle(I/C) : C Enter

The radius of circle : ( give the value of R) enter

This will generate a polygon circumscribed about a circle.

TO DRAW A POLYGON BY EDGE METHOD:

Command: POLYGON enter

Number sides: 6 enter

Edge/{Center of polygon} : E enter

The first endpoint of edge : ( click on P1)

Second endpoint of edge: (click on P2)

Good Collection. Useful And Amazing Knowledge

Thanks for your supportive comments. Stay tuned.