Auto Cad 2006

A u to C a d 2006 Prepared by Muhammad Khalil Ansari 0321-6433274 www.khalilansari.webs.com [email protected]

1

Training Programme

2

1.

Need

The use of drawings for various designs is increasing day by day. The use of AutoCAD software for preparation of engineering drawing has created a huge demand for skilled workers in this field. PVTC has therefore introduced this course to enable the poor segment of the society to earn their living with this skill.

2.

Objectives

To enable the trainees to prepare engineering drawings on computer using AutoCAD.

3.

Skill Requirements

After the completion of this course, the pass-out will be able to perform the following tasks. 1. Use a computer for making engineering drawing with the help of AutoCAD. 2. Read a simple sketch and make a drawing. 3. Start a drawing and set its unit limits on AutoCAD screen. 4. Dimensioning techniques and text writing. 5. Prepare isometric drawing & multi view projections. 6. Use measuring instruments/tools to take measurements of objects. 7. Make common types of drawings using AutoCAD. 8. Creation of 2D-3D images. 9. Prepare 3D modeling & its editing. 10. Rendering after applying material & lights. 11. Plot drawings to various scales.

4.

Knowledge Requirement

After the completion of this course, the pass-out would have the knowledge of following: 1. Types of engineering drawings and how to read than. 2. Measuring units, drawing limits, dimensioning and scales. 3. Basic terminologies and their interpretation including.
Basic engineering / manual drawings.
Basic engineering processes and operations.
Fasteners, threads and their applications. 4. Measuring tools/instruments. 5. Engineering standards. 6. Computer, it’s components and peripherals. 7. Application of AutoCAD to make engineering drawings. 8. Creating of 3D view, orthographic & isometric projections. 9. Plotting of drawings.

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10. Record keeping of drawings. 11. Basic computer, Windows, Cartesian coordinate system & use of layers.

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Entry Level


Matric (with computer knowledge)




Admission is subject to passing a general aptitude test.

6.

Class Size


7.

20-25 Trainees

Training Duration / Scheme a)

VTI Training

-03 months (theory & practical)

b)

No. of hours per week

-24

c)

Ratio (Theory to Practical)

-20:80

d)

Training material

− Trainee manual/instructor manual / standard books on AutoCAD

e)

Medium of instructions

− Urdu / English

f)

Method of instructions

− Lectures, demonstration & practical

g)

− Quizes, Fortnightly test,

Tests

and Final examination. h)

Evaluation

− Attendance, sessional, final test and OJT

i)

Qualification and Training level of staff: -Jr. Instructor

−BCS having qualified a training course in AutoCAD with 1 year experience.

- Lab Assistant

−Having adequate computer usage experience.

8. Employability The pass outs of this course will have following opportunities for employment.


Self employment.

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Design offices relating to: a. Mechanical Engineering. b. Civil Engineering. c. Town Planning Engineering. d. Architectural Engineering. e. Electrical Engineering. f. Surgical Industry. g. Football Industry.

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9. List of Tools and Equipment Sr. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Equipments

Qty

Main Servers configured to support 20-25 workstations with windows XP. PCs for workstations adequately configured, with windows XP workstations. Printer laser jet Printer inkjet Scanner flat bed Complete Networking Kits (with latest tools) Laboratory, adequately designed for computer usage, air conditioned and complete wiring and electrical fitting. Common tools for maintenance (plier, tool kit) Software: windows latest Ms office, AutoCAD, CorelDraw UPS Ink plotter for AutoCAD drawings Digital camera Bloare Laptop latest Multi media Stapler, puncher, Pin Remover

01 25 01 01 01 As per need As per need As per need 01 CD each 01 01 01 01 01 01 01 each

10. List of consumables Sr.

Items

1 2 3 4 5 6 7 8 9 10 11 12 13

Paper A4 size 10 + Legal 5 Drawing sheets 24”x18” Pencils, Eraser and sharpener Ball pen (Red & Blue) White Board Marker Refilling ink Printer cartridge for inkjet Printer cartridge for plotter Printer cartridge for laser jet Set Squares T Squares Compass Drawing board

Qty 15 Rim 100 Sheet As Required 12 12 03 03 02 02 30 30 30 30 6

14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

11. Sr. 1 2 3 4 5 6 7 8 9

Vernier caliper Steel Ruler USB Architectural scale RAM Kingston 1 GB Mouse Keyboard Note Book and Graph Paper CD Writer High lighter marker Paper cutter Gum stick Staple pin Dust cover Trainee file cover Box file Glint cleaner White board duster

12 30 01 25 10 10 10 As Required 01 02 01 02 01 box As Required As Required 03 02 03

List of Furniture & Fixture Items

Qty

Staff Chairs Staff table Student Class chair Student Lab Chair White board 4’ x 6 ‘(For Lab and Class room ) Display board 4’ x 4 ; Cabinet / Steel Almarih Side rack / computer table Desktop table for trainee

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03 01 30 30 02 01 01 01 25

12. Course Contents Sr.

Topics

Training Hours Theory Practical

1

Introduction of Computer

4

25

2

Auto CAD Fundamental

4

25

3

Object Construction and Manipulation

15

35

4

Shapes Description / Multi view Projection

3

10

5

Dimensioning Techniques

3

20

6

Analyzing 2D Drawing

3

10

7

Region Modeling Techniques

3

10

8

Isometric Drawings

03

10

9

Solid Modeling Fundamental

10

38

10

Rendering

03

15

11

Print / Plot

03

10

12

Measurement and Manually Drawing

5

20

60

228

Total

13. Distribution of Training Hours Training Hours for Theory Training Hours for Practical Total Training Hours for the Course

8

= = =

60 228 288

List of Tools and Equipment Sr. 1

Equipments

Qty

Main Servers configured to support 20-25 workstations with 01 windows XP.

2

PCs for workstations adequately configured, with windows

25

XP workstations. 3

Printer laser jet

01

4

Printer inkjet

01

5

Scanner flat bed

01

6

Networking Accessories: Ethernet Hubs, networking cards,

As per need

cables, face plates, cabinet etc, 7

Laboratory, adequately designed for computer usage, air

As per need

conditioned and dust covers with complete wiring and electrical fitting. 8

Common tools for maintenance

As per need

9

Software: windows latest Ms office, AutoCAD, CorelDraw

01 CD each

10

UPS

01

11

Ink plotter for AutoCAD drawings

01

12

Digital camera

01

13

Bloare

01

14

Laptop latest

01

15

Multi media

01

9

List of consumables Sr. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Items Paper A4 size 10 + Legal 5 Drawing sheets 24”x18” Pencils Ball pen (Red & Blue) White Board Marker Refilling ink Printer cartridge for inkjet Printer cartridge for plotter Printer cartridge for laser jet Set Squares T Squares Compass Drawing board Vernier caliper Steel Ruler USB Architectural scale RAM Kingston 1 GB Mouse Keyboard

Qty 15 Rim 100 Sheet As Required 12 12 03 03 02 02 30 30 30 30 12 30 01 25 10 10 10

List of Furniture & Fixture Sr. 1 2 3 4

Items Staff Chairs Staff table Student Class chair with Drawing Table Student Lab Chair

5 6

White board 4’ x 6 ‘(For Lab and Class room ) Display board 4’ x 4 ;

10

Qty 03 01 30 For 30 Student 02 01

Chapter # 1

INTRODUCTION OF COMPUTER Computer: A computer is an electronic device that can accept data, store it, arithmetically and logically process that data and give useful results from that processing. A computer is normally considered to be a calculating device which can perform arithmetic and logical operations at a very fast speed.

Uses of the Computer: Some common purposes of a computer are: 1. We can store data in a computer and retrieve stored data when we needed. 2. We can send message to our friends, relative and family anywhere in the world by connecting computer with Internet. 3. Computer are use to make good defense of a country. 4. Computer is helpful in offices, sciences laboratories, education, engineering and technology. 5. Medical science and biotechnology are using computer to diagnose the diseases of a people. 6. We can play game on a computer. 7. We can watch movies on a computer.

History of Computer: Abacus: The earliest device that qualifies as a digital computer is the Abacus. The Abacus was invented 5,000 years ago in Asia, Minor is still in use today. This device allows user to calculate, by sliding beads arranged on a rack.

First Generation of Computer (1945-1956) Second Generation of Computer (1964-1971) Third Generation of Computer (1971 Present) Fifth Generation of Computer (present- Beyond)

Types of Computers On the basis of principles of construction, computer is divided into three types: 1. Analog Computer 2. Digital Computer 3. Hybrid Computer

1 Analog Computer: Analog quantities show the continuity of specified value, Analog devices, which are used to measure continuous values. An example is a thermometer because it measures the length of a mercury column, which varies continuously. Another example is Analog clock.

2 Digital Computers:

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Digital means discrete, with digital signal every thing is described in two states either on or off. Which can distinguish between just two values 0 and 1? Digital watches are a good example of digital computer, because the time,

3 Hybrid Computers: A computer that combines the characters of both Analog and digital computer is known as hybrid computer. OR

The third type of computer is Hybrid Computer because Hybrid Computer is the combination of the properties of both analog and digital computers. This is usually found in science laboratories as the controlling device in an industrial process.

Differences between Analog and Digital computers Analog Digital 1. Analog computer works with continuous values. 2. It has very limited memory. 3. It can perform certain types of calculation 4. Analog computers are used in engineering and scientific applications. 5. Its accuracy is low. 6. Its readability is low.

1. Digital computer works with discrete Values. It can work only with digits. 2. It can store large amount of data. 3. Its speed of calculation is very high. 4. Digital computers are widely used in Almost all fields of life. 5. Its accuracy is comparatively low. 6. Its readability is high.

Classification of Computer Computers are classified according to size. Speed and memory, capacity .Computer is of different classification: 1. Super Computers 2. Mainframe 3. Mainframe 4. Micro/Personal Computer /Desktop or tower 5. Laptop.

1 Super Computers 4 The micro Computer /PC/Desktop or tower These computers are used now A days commonly and these computers revolutionized the computers industry because of their size and cost. • They are cheap and easy to use and out put capacity. • They have limited input • They have low storage capacity. • Hard disk and floppy disk drivers are used to enter and store data and programs. • A visual display screen and / or a printer are used to get the output. • Today’s micro computer work better then early age of Mainframe computer.

5 Laptop Computers These are light and compact and called portable because they work on batteries and can operate without an external power source. Laptops, which weigh from four to eight pounds, are often called notebook PCs because they are about the size of a one inch thick note book. 12

Operating System: A master kind of software that controls your computer and its applications is called operating system. 1. DOS 2. UNIX 3. ZENIX 4. OS-2 5. Windows- 98 6. Windows -95 7. Windows -2000 8. Windows-Me 9. Windows 10. -XP

DATA Information given by the operator which manipulates and process by the Computer is called Data. These are three types of the data.

Different types of data: Alphabets

(a-z) NUMERIC (0-9) Alphanumeric (43, Lower Mall,) Graphics Audio Video Alphabetic Data This type of data id consist of Alphabetic Data “A to Z” Special Symbol @,#,$,* Numerical Data This type of data consist of digits “0 to9” Special Symbol 1-X Alphanumerical Data This type of data consists of alphabetic character, numerical digits and special symbol.

Units and media of storage: BIT 1byte 1024Byts 1024KB 1024 MB 1024 GB

= (Binary Digits) (0, 1) = 8 bits (10010010) = 1 KB (Kilo Byte) = 1 MB (Mega Byte) = 1 GB (Gaga Byte) = 1 TB (Tetra Byte)

Part of the Computer: CUP (Center processing of Unit) 1. Monitor 2. Key board 3. Mouse

Type of Memory: 13

Primary Storage Unit. Secondary Storage Unit. RAM (Random Access Memory) ROM (Read only Memory)

Input Devices: 1. Key board i. Type writing keypad. ii. Numeric Keypad iii. Special Function Keys 2. Pointing and Draw Devices: i. Mouse ii. Joystick iii. Mouse pen iv. Image Scanner v. Digital Camera. vi. Microphone.(Sound Recorder)

Output Devices: 1. Printers: • Dot-Matrix Printers • Laser Printer • Ink-Jet Printer 2. Flat-Panel Monitors 3. Touch Screen Monitor

Abbreviations • • • • • • • • • • •

LAN: Local Area Network WAN: Wide Area Network BIOS: Basic input output System MIPS: Million instructions Per Second CNC :Computerized Neumatic Control Machine BASIC: Bigner all purpose Symbolic Instruction Code RAM: Random Access Memory ROM: Read only Memory CD-ROM: Compact disk (Read only memory) DOS: Disk Operating System ALU: Arithmetic Logical Unit

It is an electronic device that receives produces useful information according instruction. The word “Computer” is word “COMPUTE” that mean to works like a calculator but it is more and more power full (fast). It produces result like a human being capabilities are much more, it works

data,

and to derived from calculate, it intelligent but its much faster.

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Does not produce errors, process a lot storage and get bold.

Central Processing Unit The heart of computer, which accepts data from an input device for processing. The data is stored in internal memory of the processor and after logical and computational operation by mean of the instruction give by the program. The results are transferred to an output device.

CPU has the main following Unit: RAM (Random Access memory) This memory use to store the information that is to be processed. The information store in the memory lost when ever the computer is shut off. ALU (Arithmetic Logical Unit) All the information is analysis in ALU being control by the main processor CU (Control Unit) It controls the over all function of a computer and flow of information with a computer system. It also interprets and executes the instructions. Hard Disk Hard disk is used to store lot of information. A hard disk is a Sealed Vacuumed Box. Containing magnetic plates, Motor and read write head. While you are considering or comparing the personal Computer system you should note the following features of the system:1. Processor model speed in MHz 2. Math co-processor Required for extensive mathematically used) 3. RAM available, and Maximum RAM 4. Cache Ram available (High Speed Ram) 5. Floppy Diskettes Drive 6. Serial and parallel Ports 7. Hard disk campsite (in GB) 8. Key board 9. Display Monitor, Mouse

Computer System Making a Computer Alive To turn the power on and by loading the Disk Operating system in to the computer temporally memory, able to work for us, this process is called booting system. Cold Boot Means to boot up the computer by turning power on. Warm boot Means to reboot a running Computer by processing Ctrl+Alt+Delete Bit Binary digits the smaller unit of a computer data represented by 1 (which specify on state of an electrical impulse) or 0 (No electrical impulse) Byte A smallest addressable unit in memory is string of 8bit representing 1 byte. 1byte can represent a letter number a symbol or space.

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Compact Disk (read only memory) It is an optical disk having read only memory. On these diskettes the laser beam records information. They can store large information. This information cannot be removed from CDs. Character A single Letter, Number or symbol is called Character. Chip An integrated circuit made by etching a number of transistors and other electronic components onto a wafer of silicon, having a fraction of inch an each side. Command An order to the computer to executes a particular task. Cursor A patch of light on a screen that shows where you are in the text. Function Keys A Key that causes the computer to perform a Specific task. The use of most function Keys will vary by the software package being used. Hard Copy A printed Copy of information generated by a computer with the help of printer it is also called printed copy. Icon A symbol displayed on the screen to represent an option for a specific task. Menu A listing of program or option displayed on the monitor to assist in using software. Modem Modem is a short word from modulator/demodulator .A device that allows a Computer to send and received information over a telephone line. Network A series of interconnected microcomputer or terminal is called networking. Peripherals Accessory parts of computer systems that are not considered essential to its operations, including, printer, Modem, and external storage unit. Printer An output device that produced a printed copy of the objects. Information generated by a computer. Hardware The physical units that make up a Computer are called hardware. Computer hardware including a Keyboard, Monitor, CPU, and other attached unit called peripherals. Software Set of instruction (Program) and related information stored in computer system or storage media is called software.

Language Words and their usage rules (Grammar) make up a language.

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A Computer language is a set of instruction and their usage rules (syntax) each language has a defined set of instruction in their syntax (usage rules) There are three types of language:1. Low-level language 2. High-level language 3. Middle-level language

Package A package is a preprogram software, designed to performed a specific type of job. A package is developed in a programming language.

What is a File? A group of related records can be referred to as file; a named collection of information stored on a computer system is called a file.

What is a PROGRAM FILE? Program files contain the program that your Computer runs. Program file usually has EXE, or COM extension.

What is a SYSTEM FILE? System files contains information about your computer hardware and are some time called device driver. These files usually have “SYS” extension.

What is a Directory / Folder? A disk can hold several hundred of files. The more files you have more difficult to keep track of them. This help you keep track of your file, you can use MSDOS Command.

Microsoft Windows XP Operating System: Operating system is system software used to computer operations. An operating system is to allocate resources to manage disk and file, and resource in computer. You can never run a without an operating system. Some well known systems are. Windows, UNIX, Linux, OS/2, Macintosh etc.

control all responsible to allocate computer operating Apple

Windows Operating System: This operating system is developed by Microsoft 1990 Microsoft gives Microsoft Windows 3.0. After Windows 95, Windows 98, windows 2000 and windows

Features Of windows XP: We prefer Windows XP on other windows version due to following reasons.

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Company. In updating it the XP is released.

1. Plug and Play. Windows XP has ability to run a new hardware automatically when it

plugged in computer this is due to large driver’s data base in it. Window XP has ability to accept every software installed on it without restarting computer. This functionality called Hot Boot. 2. Hot Boot.

3. 33-D Graphics: Window XP gives 3 Dimensional graphics to give an attractive look. 4. Large Network Support: Window XP gives large network support and tight security options, when we make our computer part of a network. 5. Standard Menu: All related options in windows XP are grouped in standard menu.

User Account: When more then one people work on a same computer, then to control and manage each user work separately we need user account. Each user is given a user name and password (code) related to its account. We can enter in an account and can also exit from an account and can put a separate checks and securities on each account. Log On: Option used to enter in an account. You have to enter in an account when you start computer and when you switch between accounts. Log Off: Option used to exit from an account. Log Off Computer: Computer: Option used to power off your computer.

Desktop: Desktop is the first and main interface of windows operating system. You can interact with computer hardware and can use computer software from this interface. The back picture on desktop is called background. You can change background of desktop. Desktop has icons, free Area and taskbar on it. Pr.1: Log On and Log Off from an account To Log On in specific a accounts. Steps. Click on accountenter password.

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To Log Off from account. Steps. Click start buttonLog offLog off

Pr. 2: Changing Desktop Background Steps: Right click on desktop propertiesdesktopselect pictureapplyok

Pr. 3: Logging off Computer. Steps: click on stat buttonlog off computerTurn off

Pr-4: Practical of lesson 1.3 of Typing Tutor

Desktop:

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Desktop is the first and main interface of windows operating system. We will interact with computer using desktop. It contain icons, free Area and taskbar on it. Icon s.

Icons

Free Area

Task bar

Icons are small pictur e with label or name. Under an icon there will be

group of related functions. 1. Right Click on icon Open. 2. Double Click on icon. Taskbar. It is a bar at bottom of desktop. When you run or open a program it appears as button on taskbar. You can switch between multiple applications by clicking relative button on taskbar. A taskbar has four parts. Men u.

A menu is stack of options. An option is a written command used to perform a task in computer. A menu display by two methods. 1. Right Click on anywhere in computer. 2. Click on any button in Computer. Start Button

Quick Launch bar

Application bar

Status Tray TrayApplication

Windows (Dialog Box Windows): A window is simply frame region. Each dialog box window will be activated by opening an icon or clicking on a menu option. Every program will use a dialog box window to perform its functionality. A dialog box window consists on different components. It depends on dialog box functionality that how many components it has but one component essential on it is called title bar.

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Elements of Standard Dialog Box Window. A standard dialog box window has following elements. Restor Minimiz Close

Title Menu

Tool Address bar

Scroll bar

Display area Status

Title Bar: Bar Title bar has title of dialog box window. It has minimized button used to wrap up window and to put on taskbar. Restore button used to decrease size of dialog box window. Close button used to close dialog box window. Menu Bar: It has different buttons that gives a menu when we click on icon. Toolbar: Toolbar Have different icon on it to perform a task in computer. Address Bar: Address Bars tell the current location of computer. Display Area: Will display messages or items in dialog box window. Status Bar: Tells status of the selected item. Scroll Bar: Used when items are large but space or area to display then is small. Two types of scroll bar are horizontal and vertical. Pr.1: Change name of the icon. Right Click  Rename  Give name Pr.2: Customizing taskbar. Right Click on Taskbar  properties  select setting  Apply  Ok.

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My Computer: My Computer is main icon in computer. Each storage device will be displayed in it and you can control and manage all hardwires and software’s of computer.

Storage Device Representation: As we discuss all storage devices shows under my computer icon. Here hard disk is shown divided in logical parts for best data management. First part of hard disk will always assigned name C second D third E and so on. After hard disk part then next will CD drive and the next character will assign to flash drive as shown. We store all data here.

For Example: As in our case if your Hard disk has 4 parts then C, D, E, F will hard disk and G will CD drive icon. Similarly flash will assigned nest alphabet H.If other devices attached with computer then it will also represented in My Computer icon.

Control Panel: All computers controlled from control panel. It used to control, manage and change setting of your hardware’s as well as softwares.You can change your mouse and keyboard setting. You can also add and remove software from it. We can make regional setting and control speaker’s printers etc in computer from control panel.

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Steps: StartControl panelmouse iconbuttonscheck onapplyok.

Steps: My computerright click on storage devicerenamegive new name

Steps: Put CD in Cd driveMy ComputerOpening CD.

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Data Management All data in computer is managed in files and folders. Each file and folder stored on storage devices of computer may on hard disk, flash, CD etc. We usually use Hard disk to save data in computer.

File: File is a basic data storage object in computer means we save all data in files. Different files used to store different data types. To make and manage a specific file in computer we use a specific software. For example: if you want to store drawing in computer you will use paint to make drawing file (Bitmap File). Similarly if you want to save text in computer you will use text file that will be created and managed in Word pad, Notepad or Ms- Word software’s.

Folder: Folder is container of files and sub folders. We group all related For example if you want to keep record of a school then to save all record good management you should keep all files related to 10th class in one related to 9th class in other folder.

files in one folder. we will use files. For folder and all files

Naming a File&Folder: Each file and folder will be identified by a unique name. At a same storage location no two files or folders can be created or saved with same name. It is a good practice to name a file or folder related to data in it. For Example: If a file have admission from stored in it then name it as admission form. We can create, rename, delete, restore and shift a file or folder from one location to another.

Recycle Bin: Recycle bin is an object on desktop used to keep deleted item (files / folders) in computer. We can also restore (get back) file/folders from recycle bin. We can check deleted items in recycle bin as. Steps: Open recycle binSee your required item.

Shifting a File & Folder: You can move a file or folder from one location to another using copy, cut & paste command. Copy: Used to make a duplicate of current file or folder. Steps: Right click on file or folder being copied copy. Cut: Used to completely pick a file or folder from current location. Steps: Right click on file or folder being copied cut. Paste: Used to keep cut or copied file or folder on new location. Example: We have a file on D drive of name Ali Ejaz. We want to more it for D to E drive then we will use cut to shift it completely and copy to make its duplicate.

Searching File & Folder: older If we want to open a file or folder we should know about its name and location where it was saved. If we have forget location or name than you can find by search option. we should have to give part of file name or some text of the file.

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Pr-1: Creating a File and Folder: We make/create a file in two ways. Steps: 1: By using software will be explained next. 2: Right click anywhereNewSelect a file typeGive name to file. To create a folder. Steps: Right click anywhereNewFolderGive folder name

Pr-2: Renaming a File & Folder: We can change name of a file as. Steps: Right click on file  rename  give new name  ok. To change name of folder. Steps: Right click on folderrenamegive new nameok

Pr-3: Deleting a File & Folder: We can delete a file as. Steps: Right click on file being deleted deleteyes. To delete a folder.

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Steps: Right click on folder being deleteddeleteyes. Pr-4: Restoring Files and Folders: Steps: Open recycle bin  right click on deleted file or folder  restore. Then file will go back form where it was deleted.

Pr-5: Moving a File Naming Ali Ejaz Completely from D to E drive. Step 1: Open D drive  right click on Ali Ejaz  cut. Step 2: Open E drive  right click  paste.

P r-6: Sea rch ing a file wit h na me Ali Ejaz in my computer. Steps: Start Search  For file and folderFile name “Ali Ejaz” All drivesSearch. Pr-7: Practical of lesson 1.4 of Typing Tutor

Opening Programs Programs: We can active programs in computer form three ways. From start menu using all programs options, activating from shortcut on desk top, and from start menu using run option.

Program Short Cut: Shortcut used to quickly activate a program in computer. To create short cut of a programs go on it in start menu.

MSMS-Paint: MS-Paint is software used for drawing in computer. We can make drawing in MS-Paint, can save file and can also open saved files. We draw shapes in paint using toolbox. Select related tool and draw in drawing area

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Working Area

Practical: Pr-1: Creating Short cut of Programs. Steps: StartAll ProgramsRight click on required program Send to (create shortcut) desktop.

Pr-2: Activating MS-Paint. 1: We activate paint in three ways. Start  All Programs  Accessories MS- Paint. 2: Open From Run. Start  Run  Type the “mspaint”  Ok 3: Click short cut on desktop. Pr-3: Activating MS-Word. 1: We activate MS-word in three ways. Start  All Programs  MS- Word. 2: Open From Run. Start  Run  Type the “winword”  Ok 3: Click short cut on desktop. Pr-4: Activating MS-Excel. 1: We activate Excel in three ways. Start  All Programs  MS- Excel. 2: Open From Run. Start  Run  Type the “excel”  Ok 3: Click short cut on desktop.

Select

Pr-5: Activating MS-Power Point. 1: We activate Power Point in three ways. Start  All Programs  MS- Power Point. 2: Open From Run. Start  Run  Type the “powerpnt”  Ok 3: Click short cut on desktop.

File

Pr-6: Working in MS-Paint (Saving and Opening File): Open paint and make drawing in MS-paint.

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Saving file in MS-Paint. Steps: File menu save  Give location/place to save file  Give name of file  Save. To Open a saved file in Paint. Steps: File menu  Open  Select location where file was saved  Select required file being opened  Open. Pr-7: Practical of Lesson 1.5 of Typing Tutor

Question s 1. Writ e small notes on the following. 1. D e s c ri b e t

2.

he various elements of Windows XP. Desktop. 2. Write a note on MS Paint. 3. Write a note on Word Pad. 4. Describe various features of Windows XP. 5. Write a note on My Computer. Fill in the blanks. 1. Windows XP is a ___________________________. 2. Recycle Bin is used to _________________________. 3. To Save a File in Word Pad ___________ short cut key is used. 4. Windows XP is a __________ Task operating system. 5. are __________ _________ & __________.

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Chapter # 2

AutoCAD Fundamentals

Welcome to the world of Computer Aided Designing (CAD), CAD is used as a tool to produce all types of Engineering Graphics drawings whether they be two-dimensional or threedimensional or whether they be architectural, Electrical, or Mechanical in application.

Drafting and design has always been compared to language such as English or German, however, the design process and the ability to compare a design technically on paper was and still is considered the language of Industry. Due to evolution of Computer, the design has shifted from paper to the video display, although paper output through a plotter is still considered in some applications. The same tools that were available for the manual production of drawings have changed considerably using computer and in some cases doubt on the justification of the CAD terminal versus the drawing board. Now with 3D graphics available on most CAD systems, an individual not only is able to construct in three dimensions, but is also able to construct a prototype called solid model to be used for analysis.

The AutoCAD drawing Screen – Typical Installation When performing a typical installation, and when first launching AutoCAD, the AutoCAD Graphic Screen is In the screen is the pull down menu area used to locate various commands under such categories FILE, EDIT, VIEW, INSERT, DRAW, MODIFY, (a name of few) Directly beneath the pull down menu area is the Standard Toolbar containing such command as new and open in addition to displaying numerous fly outs supporting the ZOOM, OBJECT SNAPS. (And below the Standard Toolbar) Object Properties toolbar is designed to manipulate Layers, Line types and colors. Two additional toolbars appear on the left side is Draw toolbar holds the command Circle Arc, and BHATCH and Modify toolbar contains Fillet, Chamfer,

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Erase, Explode, Trim to name just a few. At the part of the display screen is the Command area which prompts you for input depending command currently in progress. At the very bottom is the status area.

USING KEYBOARD FUNCTION KEYS A typical keyboard complete with function key above the alphanumeric keys. These functions keys are labeled F1 through F12 only keys F1 through F11 will be discussed here. F1 = Windows Online Help F2 = Toggle Between Graphic Screen / Text Screen. F3 = Toggle OSNAP setting dialogue box. F4 = Toggle tablet mode on or off. F5 = 3 Isoplane modes to construct isometric drawing. F6 = Toggle the coordinates. On/off. F7 = Toggle the display of Grid on or off. F8 = Toggle to Ortho mode. F9 = Toggle Snap mode on or off. The SNAP command sets the current snap value. F10 = Toggle Polar tracking on or off. F11 = Object snap tracking on or off.

METHOD OF CHOOSING COMMANDS There are four ways to enter or select commands for or editing drawings. In figure the pull down menu is becoming with many users. The Optional screen menu is illustrated in to activate it choose the Option command located under the down menu area click on the display tab and place check in o display the screen menu. This practice is popular for users commands illustrated in figure below is an example of the method for selecting commands namely through a toolbars.

30

constructing very popular figure 39-6 tools pull the edit box familiar with fourth

ACTIVATING TOOLBARS

Numerous toolbars are available to assist you in picking other types of commands. Clicking on toolbars…. Displays the toolbars dialogue box illustrated in figure by default four toolbars are already loaded or active in all drawings they are Object Properties Standard Toolbar Draw and Modify, to make another toolbar active click in the empty box next to the name of the toolbar. This will display the toolbar and allow you to preview it before making it a part of the display screen, Commonly Command Aliases To assist with the enter AutoCAD commands from the Keyboard certain commands have been shortened and are censer considered “Aliases”. Once you are comfortable with the Keyboard using command aliases provide a very fast efficient method of activating AutoCAD commands. A AL AR BO BR C CH CHA CO D DAL DAN DBA DCE DCO DDI DED DI DIV DLI DO PE PL PO POL

ARC AUGN ARRAY BOUNDARY BREAK CIRCLE DOCHPROP CHAMFER COPY DDIM DIMALIGNED DIMANGULAR DIMBASELINE DIMCENTER DIMCONTINUE DIMIAMETER DIMEDIT DIST DIVIDE DIMLINER DONUT PEDIT. PLINE. POINT. POLYGON.

I IN INT LA LE LEN LI LT LTS M MA ME MI ML MO MS MT O OS P

31

DDINSERT. INTERFERE. INTERSECT. LAYER. LEADER. LENGTHEN. LIST. LINETYPE. LTSCALE. MOVE. MADCHPROP. MEASURE. MIRROR. MLINE. DDMODIFY. MSPACE. MTTEXT. OFFSET. DDOSNAP. PAN.

DST E ED R EL

DIMSTYLE ERASE DDEDIT REDRAW. ELLIPSE

Using the Options Dialing Box Picking the tools areas of down menu area in exposes the Option located at the very the pull-down menu. Pick command to make changes to the operating environment of the AutoCAD. Seven or Tabs are available to to make AutoCAD including to how files are the performance of the

the

pullFigure command bottom of this various

categories allow you change pointed to system.

The display and pointer will be discussed in detail in the following pages. Checking on the display tab activates the dialog box illustrated in a Figure 3-13.

Changing the Color of the

Display

Change the Colors button of the activates The AutoCAD Window box in Figure. Use this to make makes up the display screen. This easier way to manipulate screen Colors.

Display. Tab Color dialog change so that provides an AutoCAD

Changing the Size of the

Cursor

Checking the pointer tab of

the

main

Option dialog box activates

the

dialog

box shown is Figure. Here the

size

of

graphic cursor may be changed. By default the curser is displayed at 5 percent of the size of the display screen.

Starting a New Drawing To begin drawing file. Select

the

command with the button

shown in the

following

sequence; or

command

32

NEW

click on the new command located in the File pull-down menu area in Figure 3-16. The New command can also be entered in at the command prompt similar to the following command sequence: Command: NEW

Entering the NEW command displays the New Drawing dialog box illustrated in Figure 3-17. Four options are

available

this dialog box. Using a

template,

Starting from scratch, Open

an

drawing

Wizards.

and

Using

in

a

existing

Clicking on the button entitled “Start from Search” begins the AutoCAD drawing file with such default setting as a sheet of page 12 units by 9 units and four place decimal precision.

Using the Quick Wizard When clicking on the “Use a Wizard” button in addition on the Quick setup displays the dialog box shown in Figure which consists of two tabs identified by Step 1 & Step 2. Step 1 is used to graphically control the units of the drawing. Five units of measure are available through this Wizard namely Decimal Engineering, Architectural, Fractional, and Scientific. When complete with setting the unit of the drawing. Click on the Next button for the next dialog box in the Quick Setup. Step 2 of the quick Wizard setup. This tab deals with the area of the drawing which is given as a Width and a Length value Figure 3-20.The width and length of the drawing area are entered.

Using

the

Advanced

Wizard

The advanced setup dialog box Figure.3-21. The Advanced seven tabs to make changes to the setup. It is used to allow you to Decimal, Engineering, Fractional, and Scientific units. the units, they will preview in the image.

illustratedin Wizard contains initial drawing choose among Architectural, When changing Sample Units

The second tab, Step 2 of the Wizard, deals with how angles (see Figure 3-22),

Advanced Setup will be measured

33

The third tab, Step 3 of the Advanced

Setup

box, displays how angles will be

measured in the

drawing.

By

default,

angles

dialog

are

measured

starting with East for an angle of 0,

North

angle of 90 degrees, West for 180

degrees,

and

South for 170 degrees.

default,

these

Also by

for

an

angles are measured counterclockwise. The fourth tab, Step 4 of the Advanced Setup dialog box, deals with Angle Direction. As noted in Figure 3-23, all angles are by default measured in the counterclockwise direction. The fifth tab step 5 of the advanced setup dialog box is identical to step 2 of the quick wizard setup.

Opening an Existing Drawing The OPEN command is used to edit a drawing that already exists or has already been created. Select this command from the “File” area of the pull-down menu area.

Using the Browse Button Clicking on the Find File button of the Select File dialog box displays the Brows/Search dialog box illustrated in Figure 3-32. Use it to preview groups of drawings; select the desired file to open it as the current drawing file. Clicking on the Search Tab activates a dialog box. Enables you to enter drive information, file type information, and dates and times of the file in order to perform a search.

Using the Units Control Dialog Box The Units Control dialog box is available to intermediately set the units of a drawing. This dialog box is selected from the pull-down menu under “Format” Selecting Units Activates the dialog box illustrated in Figure 3-33.

The following methods of measuring in

the

angles Units

are

supported

Control

dialog

box: Decimal Degrees,

Degrees/Minutes/Seconds,

Grads,

Radians,

Units.

and

Surveyor’s

34

Accuracy of decimal degree angles may be set between zero and eight places. Selecting “Direction” in the Units Control dialog box displays another dialog box called Direction Control. Use this dialog box to conrol the direction of angle zero in addition to changing the way angles are measured by default in the counterclockwise direction.

Using the LIMITS Command

By default, the size of the drawing display screen in a new drawing file measures 12 units in the X direction and 9 units in the Y direction. As this size may be ideal for small objects, larger drawing requires a more drawing screen area. Use the LIMTS command for increasing the drawing area. Select this command form the “Format”area of the pull –down menu (see Figure 1-34 A) This command may also be entered directly at command prompt. Illustrated in Figure 3- 34B in a section view drawing. This drawing fits in a screen size of 24 units in the X direction and 18 units in the Y direction. Follow the promt sequence below for changing the limits of a drawing. Command: LIMITS ON/OFF/ Enter to

:24,18

Before continuing, perform a ZOOM-All to change the size of the display screen to reflect the changes in the limits of the drawing. This command can be found in the View pull-down menu area, clicking on Toolbar, and placing a check in the box next to Zoom. Command: ZOOM All/Center/Dynamic/Exents/Left/Previous/ Vmax/ Window/:ALL

35

Limit Settings for Typical Sheet Sizes SOALE ANSI “E”

SCALE FACTOR

DECIMAL SCALES ANSI “A” ANSI “B” 11” * 8.5”

17” * “11”

ANSI “C”

ANSI “D”

22” * 17”

34” * 22”

44” * 34”

1.00=1 2.00=1

8 4 2 1 50

88.68 44.34 22.17 11.85 5.5,4.25

136,86 68,44 34.22 17,11 8.5,5.5

176.136 88,68 44,34 22,17 11.8.5

272,176 136,88 68,44 34,22 17,11

352,272 176,136 88,68 44,34 22,17

ARCHITECTURAL SCALES SOALE SCALE ANSI “A” ANSI “B” ANSI “C” ANSI “D” ANSI “E” FACTO 11” * 8.5” 17” * “11” 22” * 17” 34” * 22” 44” * 34” 96 88.68 136,86 176.136 272,176 352,272 88.68 48 44.34 68,44 88,68 136,88 176,136 44.34 24 22.17 34.22 44,34 68,44 88,68 22.17 16 11.85 17,11 22,17 34,22 44,34 11.85 12 5.5,4.25 8.5,5.5 11.8.5 17,11 22,17 5.5,4.25 6 88.68 136,86 176.136 272,176 352,272 88.68 METRIC SCALES SOALE SCALE ANSI “A” ANSI “B” ANSI “C” ANSI “D” ANSI “E” FACTO 11” * 8.5” 17” * “11” 22” * 17” 34” * 22” 44” * 34” 1=1 25.4MM 279,216 432,279 559,432 864,559 1118,864 1=10 10CM 110,85 170,110 220,170 340,220 440,340 1=20 20CM 220,170 340,220 340,220 680,440 880,680 1=50 50CM 550,425 850,550 1100,850 1700,1100 2200,1700 1=100 10CM 1100,850 1700,1100 2200,1700 3400,2200 4400,3400 Using the GRID Command Use grid to get a relative idea of the size of objects. Grid is also used to define the size of the display screen originally set by the LIMITS command. The dots that make up the grid will never plot out on paper even if they are visible on the display screen. Grid dots may be turned on or off either by using the GRID command or by pressing the F7 function key. By default, the grid is displayed in one unit intervals similar to Figure 3-38. Command: GRID Grid spacing (x) or ON/OFF/Snap/Apect :0.50 While grid is a useful aid for construction purposes it may reduce the overall performance of the competer system. If the grid is set to a small value and is visible on the display screen, it takes time for the grid to display. If a very value is given display warning that a prompt will be displayed warning that the Grid value is too small to display on the screen.

36

Using the SNAP Command It is possible to have the cursor

lock onto or

snap to a grid dot this is the

Purpose of the

SNAP command. By default

the

snap spacing is 1.00 units.

Even though a

value is set the snap must be

turned on for

the cursor to be positioned on a

grid dot. This

can be accomplished by using

the

current

SNAP

Command below or by pressing the F9 function key. Using the Drafting Setting Dialog Box Selecting “Tools” from the pullarea

and

then

down

selecting

menu

“Drawing

Aids…” displays the Drawing

Aids

dialog

box used for making dynamic

changes

to

such commands as GRID and

SNAP.

In

addition to these command the

following

command modes may also be

changed:

Ortho: Solid Fill: Quick Text;

Blips;

Highlight, grouping; And Associative Hatching Placing a check in the box provided turns on the Specific mode, checking the boxagain removes the check turning of the mode.

37

Organizing a drawing through layers As a means of organizing objects, a series of layers should be devised for every drawing. Layers can be thought of as a group of transparent overlays that combines to from the completed drawing. Fig ure 2-43 shows a drawing consisting of object lines, dimension lines, and border. Creating these three drawing components is illustrated in Figure 2-44 Only the drawing border occupies a layer that could be called be called “Object” and the

Dimension lines could be drawn on a layer called “Dimension.” At times it may be necessary to trun off the dimension lines for better clarity of the object. Creating all Dimensions on a specific layer will allow you to trun off the dimensions while viewing all other objects on layers still turned on.

Using the LAYER Command Command: LAYER ?/Make/Set/New/On/Off Color / type/Freeze/ Thaw/Lock/Unlock: A detailed listing of the LAYER option follow they are also entered in from the keyboard using the first letter of the option (except for the Lock option which requires the letters “LO” to activate it). Figure 2-43 Figure 2? Used to give a complete list or partial listing of all layers in the current drawing file. Make Use to create a new layer and automatically set the new layer the current layer. Set Allows you to change to a new current layer, layers. All new objects drawn on this layer. New Used to create n new layer or series of new layers. The set option is then used to change from one layer to new current layer. On Make all objects created on a certain layer visible on the display screen. Off Turns off or makes invisible all objects created on certain layer. Color Allows you t assign a color a layer name. Ltype Allows you to assign a linetype to a layer name. Freeze Similar to the off option; turns off all objects created on a certain layer. Objects frozen will not be calculated when performing a drawing regeneration. Therefore, Freeze is used as a productivity tool to speed up drawing performance. Thaw Similar to on turns on all objects created on a certain layer that was previously frozen. Lock Allows objects on a certain to be visible on the display screen while protecting them from Figure 2-45 accidentally being modified through an EDITING command. Figure 3-45 Unlock Unlock a previously locked layer.

38

Using the LAYER Command to create New Layer Using the Layer & Linetype Properties A more popular and efficient way to creat and is to use the Layer & Linetype Properties perform the following layer operations: Creating new layers Making a layer the new current layer Assigning a color to a layer or group of layers Assigning a linetype to a layer or group of Turning layers on or off Freezing or thawing layers Locking or unlocking layers.

Dialog Box manage layers dialog box to Figure 2-

layers Figure 2-46A

Creating New Layer Using the Box

Dialog

Clicking on the “New” button of the Layer & Linetype Properties dialog box automatically creates a new layer called “Layer1” which display itself in the layer list box in Figure 2-47 Since this Illustrated in Figure 248 is the result of changing the name “Layer” to “Objects” As the word “OBJECTS” may be entered in with uppercase, or “objects” in lower case letters, if more than one layer needs to be created it is not necessary to continually pick on the new layers a more efficient method world be to perform Figure 2-46 the following after creating n new “Layer” change its name layer name is completely highlighted, you may select to change its name to something with more meaning, such as a layer called “Objects” to hold all objects lines in a drawing the layer name is capitalized while all other letters appear in lowercase. To “Dim” followed by a comma (,) automatically create a new “Layer1” 49) Change its name followed by a new layer is created and so on.

this will (see Figure2comma and a

Assigning Colors and Linetypes Once a layer is selected from the list box & Linetype Properties dialog box and is selected next to the layer name, the dialog box shown in Figure 2-50

of the Layer color swatch select Color displays.

Use this dialog box to dynamically preloaded linetypes to be preloaded, Load button of the Select Linetype

select click on the dialog box to Figure 3-49

39

display box shown in Figure 2-52. Once the Load or Reload Linetypes dialog box is display as in Figure 2-52,

Notice in addition to standard linetypes such as Hidden and Phantom, a few linetypes are provided that have automatically embedded into the the linetype is drawn, the text is

text Layer Command Button

linetype.

Layer is Off On/Off

Select and Make A Layer Current

As

placed

Freeze/Thaw

depending how it was originally

designed.

Freeze/Thaw In a Viewport Color

Once layers have been created along with color and Lock/Unlock linetype assignments, the display of the layer & Figure 1-56 Linetype properties dialog box will be similar to Figure 3-53 Initially when layers are created, they are placed in the dialog box in the exact order they Clicking on the Details button in Figure 2-53 expands the botton of the dialog box to include more detailed information about the selected layer (Figure 2-45) Name color, and Linetype information is isolated in individual edit boxes. Also where created in. Once the dialog box is dismissed using the OK button and then revisited at a later time all layer names are reordered to be displayed in alphabetical order. The properties of the layer (On, Freeze in all viewports, etc)

Control of Layer Properties The Objects Properties toolbar displays extra buttons for the control and Figure 2-52 manipulation of layers in a drawing. The Make layer Current Button in Figure 2-55 allows you to make a layer the new current layer by just clicking on an object in the drawing. The layer is now making current based on the layer of the selected object. The presence of the light bulb Signifies that the layer is turned on. Clicking on the lightbulb symbol will turn the layer off. The symbol signifies that the layer is thawed. Clicking on the sun turns it into a snowfiake symbol signifying that the layer is now frozen. The padlock symbol controls whether a layer is locked or unlocked. By default, all layers are unlocked. Clicking on the padlock changes the symbol signifying the layer is locked. Froozing and thawing of layers viewport is also possible through this area;

Controlling the Linetype Scale LTSCALE By default value of 1.00 This scale value acts as all linetype distances. In the hidden linetype is have dashes 0.125 units value of 1.00 displays hidden line at a value of

is in effect. a multiplier for other word, if designed to long, Ltscale the dash of the 0.125 units.

40

The LTSCALE command displays the following command sequence. Command: LTSCALE (C) (B) New scale factor< 1.0000>: (Press ENTER to accept the default or enter another value) Accept the default or enter another (D) value) In Figure 2-58, (A) Command: LTSCALE Scale factor 0.50 (E) In Figure 2-59, (F) A Ltscale value of 2.00 units has been Figure 2-62 Figure 2-59 applied to all linetypes. As a result, instead of all hidden line dashes measuring 0.125 units, they now measure 0.25 as a result of the 2.00 multiplier as what appears to be continues linetype. Command: LTSCALE New scale factor < 0.5000>: 2.00 Illustrated in Figure 2-60

The Alphabets of Lines. Before constructing engineering drawing the quality the lines that make up the drawings must first be discussed. Some lines of a drawing should be made thick others need to be made thin. This is to emphasize certain part of the drawing and is controlled through a line quality system. The most important line of a drawing outlines the shape of the object and for this reason is referred to as an Object line. Because of their importance, Object lines are made thin and continuous so they can stand out among the other lined in the drawing. It does not mean the other lines are considered unimportant; rather, the Object line takes precedence over all other lines. The Dimension line is a thin line used to show the numerical distance between two points. The dimension text is placed in between the dimension line and arrowheads are placed at opposite ends of the dimension line. The Extension line is another thin continues line and is used as a part of the overall dimension. Extension lines show the distance being dimensioned. Another important line used to identify the centers of circles is the Center line. It is a thin line consisting of a series of long and short dashes. It is a good practice to dimension to centerlines. (C)

Basic Drawing Techniques Using the Command Use the Line command to construct a line from endpoint to the other. As the first point of the marked, the rubber band cursor is displayed with the normal crosshair to help see where the line segment will be drawn. The LINE command stays active until either the close is used or a null response is issued by pressing ENTER key at the prompt “To point.” Study 3-62 and the following prompt sequence below using the LINE command. From point :( Make a point at “A”) To point :( Make a point at “B”) To point :( Make a point at “C”)

41

LINE (D)

(B)

one line is along next

(A)

Figure 2-63

(E)

(F)

option the Figure for

To point :( Make a point at “D”) To point :( Make a point at “E”) To point :( Make a point at “F”) To point: Close From time to time, mistake is made in the LINE command by drawing incorrect segment. As illation in Figure 3-63, segment DE is drawn incorrectly Instead of exiting the Line command and the line a built in Undo is used inside Figure 2-64 of the command this removes the previously drawn while still remaining in the LINE command. Figure:3-63 and the following prompts to the Undo option of the LINE command. Command: LINE From point: (Mark a point at”A”) Too Point :( Mark a point at”B”) Too Point: (Mark a point at”C”) Too point: (Mark a point at”D”) Too point: (Mark a point at”E”) Too point: Undo (To remove the segment  to “E” and stil remain in the LINE command)  Too (Mark a point at F)  Too point:Endp Of select the end point of the line segment at To point: (Press to exit this command) Another option of the LINE command is the option. To pick up at the last point of a drawn line segment, enter the LINE command ENTER key. This will activate the continue LINE command. Command: Line From point: (Press – to activate Continue Too Point: (Mark a point at “B”) Too point: (Mark a point at C”) Too point: End Of select the endpoint of the vertical line element: at “A”) Too point: (Press to exit this command)

Y-Axis

X-Axis

from.

A”)

Figure 2-65

continue previously and press the option of the

choice)

Cartesian coordinates Before drawing Precision geometry such as circles, you must have an understanding of systems. The Cartesian, or rectangular system is used to place geometry at exact through a series of coordinates .A coordinate an ordered pair of numbers usually identified The coordinates are then plotted on a type of chart. The graph shown in Fig 2-65 is made perpendicular number lines called coordinate

Y-Axis

X-Axis Origin 0,0

42

Figure 2-66

lines and coordinate coordinate distances is made up of as X and Y. graph or up of two axes. The

horizontal axis is called the X-axis. The vertical axis is called the Y-axis. As shown in figure 2-66, the intersection of the two coordinate axes forms a point called the origin. Coordinates used to describe the origin are 0.0 from the origin, all positive directions move up and to the right. All negative direction maven move down and to the left. Y-Axis

The coordinate axes are divided into four four quadrants that are Quadrant II Quadrant I labeled I,II,III, and IV as shown in -X, +Y +X, +Y Figure 2-67. In Quadrant I, all X X-Axis and Y values are positive, Quadrant Origin 0,0 II has a negative X value and Quadrant III Quadrant IV positive Y value, Quadrant -X, -Y +X, -Y III has negative values; for X and Y, Quadrant IV has positive Figure 2-67 X value and negative Y values. For each ordered pair of (x,y) coordinates X means to move from the origin to the right if positive and to the left if negative, Y means to move from the origin up if positive and down if negative. Figure 2-68 shows a series of coordinates plotted on the number lines. One coordinate is identified in each quadrant to show the positive and negative values, As an example 3,2 located in the Quadrant I means to move 3 units to the right of origin up 2 units. The coordinate 5,3 located in Quadrant II means to move 5 units to the left of the origin and up 3 units. Coordinate -2,-2 located in quadrant III means to move 2 units to Y-Axis the left of the origin and down 2. lastly coordinate 2,-4 located in quadrant IV means to move 2 units to the right of the origin and Quadrant I down -4. -10,6

6,4

-8,-8

4,-8

Figure 2-68

+X, +Y

When beginning a drawing in Auto CAD the screen display reflects Quadrant I of the Cartesian coordinate system. As shown in Origin X-Axis corner of the 0,0 Figure 2-69 the origin 0,0 is located in lower left drawing screen The current screen size is measured by the upper right Figure 2-69 coordinate of the which is, by default, 12,9. This value may be change using, the LIMITS command to accommodate any drawing including architectural and civil engineering.

Using Absolute Coordinate Made to Draw Lines When drawing geometry such as lines, lines, a method of entering precise distances must be used especially when accuracy is important. This is the main purpose of using coordinates. The simplest and most Elementary form of coordinate values is Absolute coordinates Absolute coordinate conform to the following format: (X,Y) Command: LINE From point: 2, 2(at ‘A’) To point: 2, 7(at “B”) To point: 5, 7 (at “C”) To point: 7, 4 (at “D”) To point: 10, 4 (at “E”) To point: 10, 2 (at “F”) To point: C (To close the figure) 43

As you can see, all points on the object make reference to the origin at 0,0 Even through absolute coordinates are useful in starting lines, there are more efficient ways to continue lines and draw object. One problem with using absolute coordinates is that all coordinate value refer back to the origin 0,0. This origin on the Auto CAD screen is usually located in the lower left corner of a brand new drawing. The origin will remain in this corner unless it is altered using the LIMITS command. Study the following line command prompts as well as figure 2-70.

Using Relative Coordinate Mode to Draw In absolute coordinates, the origin at 0,0 must be kept track of at all times in order to enter the correct coordinate. With complicated objects this is sometimes difficult to accomplish and as a result the wrong coordinate is entered. It is possible to reset the last coordinate to become a new origin or 0, 0 point. The new point would be relative to the pervious point and for this reason this point is called a Relative Coordinate the format is as follows: @X, Y In this format, we use the same X and Y values with one exception: the “At” symbol or @ resets the previous point to 0,0 and makes entering coordinates less confusing. Study the following LINE command prompts as well as figure 271. Command Line From point: 2, 2 (at “A”) 2, 2 To point:@0,4 (“to B”) To point: @ 4, 2 (to C”) To point: @ 3, 0 (to D”) To point: @ 3,-4 (to E”) To point: @ -3,-2 (to F”) To point: @ 7, 0 (to G”) To point :( Press – to exit this command) In each command proper the @ resets the previous point. Figure 2-71

The Polar Coordinate Mode To Draw. Another popular method of entering coordinates is by polar mode. The format is as following. @ Distance