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CHAPTER ONE

WHAT IS AUTOCAD?

Lay language spoken, AutoCAD is a program designed for drawing drawings, for

example in mechanical engineering, civil engineering and surveying. There can be two-

dimensional design drawings in terms of (2D) and three-dimensional view (3D) in the

case (drawing), which lines. There are various programs for these purposes and there

are specialized programs with which you can make 2D drawing and 3D modeling

drawings and the like.

Also set the parameters of UNITS that draw drawing.

FORMAT => UNITS. AutoCAD is used as a measuring

parameter UNITS and set the settings I choose whether

to be millimeters, centimeters, meters, kilometers, etc. ...

In mechanical engineering using millimeters, centimeters

in construction and surveying meters. So this is important

for PLOT (printing on paper) and the SCALE that is placed

at the end. (Or if you want to inch or kilometer ;-)

Working in AutoCAD requires some basic knowledge of

your work, and also good to have prior knowledge base

and knowledge of the plot coordinate system.

Fig. 1.1

If you really want to learn to work in AutoCAD 2007 go through this book step by step, do not

skip because you omit something that is important for the final result of your drawings.

I can only note that all depends on you and your creativity. When drawing a drawing of the

same 5 different artists can draw the same drawing with different options, using different

lines and the like. It is impossible to strictly explain how to completely draw a sketch for

example: CONE someone can draw using the commands "CONE" someone using a

combination of CIRCLE-EXTRUDE/Taper Angle.

That's not important, it is important to draw a drawing of what is required and how to reach

the final goal is a matter of your creativity.

COORDINATE SYSTEM in AutoCAD

To work in AutoCAD is necessary to know the Coordinate System.

When we draw a line or any character or point, the start position will be set in relation to the

coordinate system.

Coordinate system understands as a plane that can be in a position if it is a 2D drawing or

more positions when it comes to drawing in 3D.

So we start from starting point in relation to the axis X and Y coordinates with the position we

are in a certain place (more about that below), but remember the word origins, to the

position which is currently located prior to drawing. Each time when we are positioned

somewhere, our starting point is the starting point no matter where in the drawing are. The

position of the origin depends on the draw in the absolute or polar coordinate system

(although we may in the course of combined systems that we want).

Be sure to learn the coordinate system, if not, then it will be almost impossible to design a

more complex 2D drawing about in 3D not to speak of. For 3D drawing, drawing a line in

space must review the toolbar UCS and UCS II, because using them will be positioned at a

starting point, surface, plane and so forth.

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Layout Coordinate System

Fig. 1.2

Short explanation of coordinate system.

Our starting point is always in the direction East and to the first X followed by Y coordinates in

direction North. (x,y).

So our starting point is the central starting point. When the Command line write some

coordinates, AutoCAD will be based on this starting point (which is currently on the drawing)

in relation to his position will be the starting point drawing.

Used as a guide to X axis first coordinate and Y axis for the second coordinate (except in

Cartography Geodesy, there are reversed coordinates - replaced, what is the X axis in

mechanical engineering and construction to the Y axis in geodesy). It is also important to note

that the axis X and Y can be so negative compared to the starting point for some sort of

starting point we can enter a drawing and negative coordinates. These negative coordinates

positioned in Quadrant II and III for the X axis, and III and IV quadrant of the Y axis

Example:

If when you start drawing enter coordinate X = 50 then Autocad X axis count by 50 units in

the East direction, depending on the value of Y axis, the result will be in quadrant I or IV, but if

you write X = -50 then AutoCAD count 50 units in the minus i.e. in the direction of West and

again depending on the value of Y axis, the result will be in quadrant II or III.

The same is true for the Y axis (Please note the Geodesy is reversed, first write the Y axis and

then X (y,x)

All of this applies to enter angles in Command Line.

"COUNTER CLOCKWISE" and "CLOCKWISE" directions are in the drawing coordinate system.

The engineering and building construction uses direction "Counter Clockwise" and geodesy

"Clockwise"

What does it mean?

Means that when we draw circular arcs, and other elements depending on the direction that

we will set our direction and drawing, the starting point to the end. By default AutoCAD 2007

in this direction is set in the Counter Clockwise direction, and that means the opposite of

clockwise. If you want to change this direction then the text menu, select Format => Units

(Fig. 1.1) and select the option Clockwise. Here is set and other parameters related to the

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units to work in AutoCAD. Or the same parameters can be set via a dialog window in the

STARTUP ADVANCE SETUP window

Fig. 1.3 Fig. 1.4

TYPES OF COORDINATES IN AUTOCAD

Explore this kind of coordinates and consider them good. The pictures to see how the

coordinates are entered in the Command Line.

These coordinates, I will elaborate

later but for now it is important to

understand the scheme and

coordinate their method of

application (under the name of the

coordinates). Course to enter

some of the following commands

to coordinate an important starting

point (starting point where we are,

on the basis of it we will choose

which of these commands

coordinates can be used.)

Fig. 1.5

Fig. 1.6

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