Autocad - Introduction to AutoCad

Beginning of a new drawing.

Start AutoCAD by clicking on the Windows Start button (bottom left), then move the mouse to Programs then AutoDesk then "AutoCAD 2008" and click on AutoCAD. 

Another method is just by clicking the icon of AutoCad 2008 in the desktop.

Once the AutoCad is loaded a black screen will appear and it is ready to be used as a new drawing.

To load a new blank drawing . Just click the drop down menu File -> New or Ctrl + N.

Another method is by typing : qnew <┘.

Then we will see a dialog box open that asks us to select a template drawing to use ( as shown below ):

Select the "acad.dwt" template file and press the Open button to continue to the drawing screen.

Once there, type in Z  E  this will zoom into to the extents of the drawing area and make it easier to see what we are drawing (NOTE: nothing will appear to happen).

Exploring and Interacting with the drawing window

Try to move the mouse around until a crosshair cursor can be seen on the screen, once AutoCAD has loaded. The AutoCAD window has a number of important features:

1. The standard Windows drop-down menus.
2. The standard Windows toolbar below the menus, it includes: File-New, File-Open, File-Save, Print .
3. In addition to the standard toolbar there will be a number of AutoCAD specific toolbars: Object Properties, Draw and Modify and etc.
4. The graphics area - that's the area where you draw - note the scroll bars and the axis label.
5. View Tabs - these 'tabs' give access to different view of the current drawing. The "model" tab should be selected at present.
6. The command area - this small window (by default) has space for three lines of text - this is where you type commands.
7. The status area, at the bottom of the AutoCAD window, this includes the current cursor position.

One of the important features of AutoCad is the command line text that should be used parallel to the command line interface .

Exploring command entry method.

There are many ways to do things in most Windows programs. AutoCAD is no exception. Everyone will develop a way that works best for him or her.  Primarily we will be working with the keystroke commands. The reason for this is because they will work in most AutoCAD versions (including DOS versions), and in some other CAD programs. 

The important thing to remember is that AutoCAD will expect you give it information in a very particular order. The most frustrating thing when you begin using this program is that you will try to do something, but AutoCAD will 'not work'. In most cases, it means that you are trying to input information at the wrong time. This is why it is very important to be in the habit of looking at the command line.

The command line tell us what information AutoCad needs to continue the operation. There are a lot of command lines but here we will mention only the command line which are normally used.

• Line - Draw a straight line segment from one point to the next.
• Circle - Draws a circle based on a center point and radius.
• Erase - Erase an object.
• Print - Enables the Print/Plot Configuration Dialog Box.
• etc....

After each command line we have to press to activate the command and just follow the requirements stated in the command text box. To terminate the command line just press or and press to restart the command. 

Drawing and UNDOing lines.

Start the LINE command and draw a line from 1,2 to 3,2 to 3,4 to 1,4 Press enter after each point.  (*Remember we have to watch the command line as we do this.) For the last line, we can either type in 1,2 or C to close the line back to the first point you entered. You have just drawn a 2" square using absolute co-ordinates. Your command history (F2 key) should look like this:

Command: L Line Specify first point:1,2

Specify next point or [Undo]:3,2

Specify next point or [Undo]:3,4

Specify next point or [Close/Undo]: 1,4

Specify next point or [Close/Undo]: 1,2

Specify next point or [Close/Undo]:

If you make a mistake, you can use the undo icon, press U or press CTRL+Z.

We can also use the ERASE command to get rid of lines you don't want. Next draw a similar box using relative coordinates . Start the LINE command and begin t point 4.5 , 2. From there draw a line two units to the right by typing @2,0 ( this means 2 units 

From there draw a line two units to the right by typing @2,0 (this means 2 units in the X direction, 0 units in the Y direction based on the last point we entered). Next type @0,2 then @-2,0then @0,-2 to finish the box. (Remember to press enter after each point.)

Now erase the last box we just drew. Start the ERASE command and then select the lines we want to erase the last box we just drew. Start the ERASE command and then select the lines we want to erase. Then press.

Draw a third box using polar co-ordinate input. Start the LINE command and begin at the point 8,2 then enter. Type @1<45>

Instead of Line we can use L as a shortcut.

Saving and opening the drawing.

Select the save icon from the standard toolbar. The drawing has not been saved before , so AutoCad will display the SAVE AS dialogue box, select the appropriate Drive and Directory (for example c:\desktop\drawing) , type the drawing name (for example Task1) and select "OK" . We can also use shortcut Ctrl+S or use the command text Qsave .

Select the open icon from the standard toolbar. AutoCad will display the Select File dialogue box and we have to select the right file that we wish to open. After that select "OK" to open the file . The shortcut of this command is Ctrl + O and the command text is Open .

Changing the GRID, SNAP and UNIT setting.

Grid is a rectangular pattern of dots or lines that extends over the area we specify as the grid limits. Using the grid is similar to placing a sheet of grid paper under drawing. The grid helps us align objects and visualize the distances between them. The grid is not plotted. This function can be activated by clicking Grid at status bar or by typing command text grid .

Snap mode restricts the movement of the crosshairs to intervals that we define. When Snap mode is on, the cursor seems to adhere, or "snap," to an invisible rectangular grid. Snap is useful for specifying precise points with the arrow keys or the pointing device. Snap can be activated by clicking Snap at status bar or by typing snap .

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 your drawing at actual size with that convention. For example, a distance of one drawing unit typically represents one millimeter, one centimeter, one inch, or one foot in real-world units.

To activate the function we have to go to drop down menu Format -> Units... or by simply typing the command text units .

Drawing CIRCLE giving center point and radius , diameter , 3P , 2P, TTR 

(Tanget,Tangent, Radius ).

There are 3 ways to draw a circle but at first to activate the command just click the Circle icon or type the command text Circle .

We can draw the circle if given is the position of the center point or if given is the radius of the circle or if given is the diameter of the circle or if given are 3 points or 2 points. We can also draw a circle if we specify the position of 2 tangents and the radius of the circle.

Drawing arcs

Select Arc icon or type Arc  . Then we have to select 3 points e.g Start point , second point and end point. Or we can select the center point of the arc , then select the center point and lastly the end point.

Using Erase , Rectangle and Distance.

We can erase the objects using several methods. 

1. Erase them using Erase function. ( Click Erase icon or Modify -> Erase or type Erase )
2. Select and cut the object using Ctrl + X.
3. Select and press delete.

To draw a rectangle just click icon Rectangle or type the command text Rectangle  or Draw -> Rectangle.

We can retrieve information about the relation between two specified points: for example, the distance between them or their angle in the XY plane.

To determine the relation between two points, we can display the

• Distance between them
• Angle between the points in the XY plane
• Angle of the points from the XY plane
• Delta, or changed, X, Y, and Z distances between them

To know the distance :

- Click Tools -> Inquiry -> Distance

- Or just type Dist

To know the position of the point 

- Click Tools -> Inquiry -> Id point

- Or just type id

Accessing AutoCad Help

We can get detail info about AutoCad in Help menu . 

- Just click F1

- Or  Help -> Help