**CADDMECH TECHNOLOGY BADDI 9857890000**

Welcome to the world of CAD - In this tutorial you will be learning the basics of CAD. The course is designed so that the commands and instructions should work on almost any version of AutoCAD, although this version is designed specifically for AutoCAD 2010. By the end of this level you will have the skills to develop basic 2D drawings and print them out to scale.

Let's start at the beginning, these things you need to know, or the rest of it won't make any sense at all. Make sure you have a very good understanding of this lesson before continuing. This lesson is longer than most, but will cover important topics. Learn it, live it.

Everything that you draw in AutoCAD is

**exact**. It will be more accurate than you will ever need it to be. We're talking 14 decimal points accurate. All objects drawn on the screen are placed there based on a simple X,Y co-ordinate system. In AutoCAD this is known as the__World Co-ordinate System__(WCS). You must understand this to know how to put things where you want them.*(3-D work has an added axis, the Z-axis, but this is not covered in this lesson.)*Below is a diagram showing you how this system works (place your mouse on the diagram for more info)..

In order to work effectively with AutoCAD, you

**have**to work with this system. Until you are comfortable and familiar with it, learning AutoCAD will be more of a chore. My experience in teaching is that the better a student is with co-ordinates, the better CAD draftsperson they will become.**Here is how it works:**

AutoCAD uses points to determine where an object is located. There is an origin where it begins counting from. This point is (0,0). Every object is located in relation to the origin. If you were to draw a line straight out to the right from the origin, this would be considered the positive X-axis. If you were to draw a line straight up, this would be the positive Y-axis. The picture above shows a point located at (9,6). This means that the point is 9 units over in the X-axis and 6 units up in the Y-axis. When you are working with points, X

**always**comes first. The other point shown is (-10,-4). This means that the point is 10 units in the negative X-axis (left) and 4 units in the negative Y-axis (down).A line has two points, a start point and an end point. AutoCAD works with the points to display the line on the screen. Move your cursor over the picture above and you will see line drawn from the points of (-10,-4) to (9,6).

Most of the time you will not have an indication of where the origin is. You may need to draw a line from the endpoint of an existing line. To do this you use points. These work the same way, but you have to add the

**@**symbol (shift+2) to tell AutoCAD that this next point is relative from the last point entered.**To review:**

ABSOLUTE POINTS are exact points on the drawing drawing space.

RELATIVE POINTS are relative to an OBJECT on the drawing space.

ABSOLUTE POINTS are exact points on the drawing drawing space.

RELATIVE POINTS are relative to an OBJECT on the drawing space.

Its a simple system, but mastering it is the key to working with AutoCAD and is explained in more detail further below.

AutoCAD measures angles in a particular way also. Look at the diagram below and then place your mouse on it to see how this is done.

When drawing lines at an angle, you have to begin measuring the angle from 0 degrees, which is at the 3 o'clock position. If you drew a line at 90 degrees, it would go straight up. The example above (when you move your mouse over it) shows a line drawn at +300 degrees (270+30), or -60 degrees.

You might not always have an obvious reference point for 0 degrees. Look at the example below and place your mouse on the image to find out the angle in question.

In this example, you are given information about the lines, but not the angle AutoCAD needs to draw the line from the start point. What you are given though, is (a) the knowledge that 0° is at the 3 o'clock position (b) the knowledge that 180° is at the 9 o'clock position and (c) the angle between 180° and the line you want to draw is 150°. With this information, you can figure out what angle you need. Here is a fool-proof way of getting the angle you need:

1.) Start at the 0° position and measure counter-clockwise (+) to 180°.

2.) From 180°, measure clockwise 150° (-)

3.) Consider that you just went +180-150 and use that as an equation: +180-150=30

Welcome to

**CADDMECH TECHNOLOGY**an Institute of Designing ( Auto Cad / Pro-E / Catia ) and any companies Project Design & Drafting tool and Die Design advance Engg. applications. For more Information**Contact :- Mahesh Sachdeva 09857890000, 09882120009**