Drawing Aids and Tools (part 2)

4.2 Using Ortho, Grids, and Snap

Ortho mode:

Ortho is abbreviated for orthogonal, which means either horizontal or vertical. Like other options on the Status bar, 'ORTHO' is not really a command, but is a drawing mode that can either be turned on/off. Using this mode you can restrict the movement of cursor in vertical and horizontal directions. This mode is very useful when you are drawing horizontal and vertical lines. The orientation of the current user coordinate system (UCS) determines the horizontal and vertical directions. In 3D views, Ortho mode additionally restricts the cursor to the up and down directions. In that case, the tooltip displays a +Z or -Z for the angle.

To turn on or off the ORTHO mode

• On the status bar, click ORTHO.

To turn the 'ORTHO' mode on/off temporarily, hold down the 'SHIFT' key while you work. The direct distance entry method is not available, while you use the temporary override key.

NOTE: Turning on ORTHO automatically turns off the polar tracking.

Perhaps, Ortho mode is the simplest & easiest of all the drawing aids, & also one of the oldest in a sense of its history. In fact, there are no special settings to make for, it is either on or off. Simply it does a very easy job i.e. it restricts the movement of drawn line to the horizontal & vertical.

Grid mode:

This drawing aid acts as a visual aid in AutoCAD drawing. It is a uniform pattern of dots that is displayed on the graphics screen. It is just equivalent of drawing on a sheet of graph paper on a drawing board. Using this mode you can enhance drawing speed and efficiency. It displays grids with spacing that you specify. You can easily control its spacing, angle & alignment.

To turn on or off Grid mode

1. Click Grid on the status bar.

or,

2. Type GRID in the command line

Command: GRID

3. Specify the grid spacing. If you don't want to change default value hit ENTER.

Specify grid spacing(X) or [ON/OFF/Snap/Major/aDaptive/Limits/Follow/Aspect]

: (number)

4. Press ENTER

5. Type ON or OFF according to your choice.

Specify grid spacing(X) or [ON/OFF/Snap/Major/aDaptive/Limits/Follow/Aspect]

: (ON/OFF)

or,

6. Click right button on your mouse at the GRID on the status bar and then choose settings.

(A dialog box will appear)

7. Click on Grid On (F7) to on/off the grid mode.

8. Click OK button.

4.3 Help and Undo Commands

Help Command:

AutoCAD provides help about all the commands and description that you require in AutoCAD drawing. You may not know all about AutoCAD drawing commands and many others things to use in AutoCAD. At the same time, when you are using CAD you may not have book next to you for help if you get stuck by something new in AutoCAD. So in this situation you can get knowledge about the drawing commands and other information using 'HELP' command. It is very useful while you are creating drawings.

1. Type HELP in the command line. Then, an AutoCAD help box will appear.

or,

2. Press shortcut command "F1"

Undo Command:

While AutoCAD drawing you may erase the object/s you don't want to by mistake. To bring it back you can use 'UNDO' command. In simple words, if you really want to bring back the objects that you deleted recently then you can use this command. So, because of this command you don't have to draw the object/s twice you erased mistakenly. Thus, this command helps to save your time.

1. Click the UNDO icon.

or

2. Choose Edit (at the menu bar), Undo.

or

3. Press Ctrl + Z

or

4. Type U (on the command line) to undo the last command.

Command: U

Redo Command:

This command performs just opposite to the Undo command.

1. Click the REDO icon.

or

2. Choose Edit, Redo

or

3. Type REDO (on the command line) to redo the last undo command.

Command: REDO

4.4 Display Commands

Zoom command:

It increases/decreases the apparent size of the drawing objects in the current viewport.

1. Click the ZOOM icon.

or

2. Choose View (on the menu bar), Zoom.

or

3. Type ZOOM (on the command line)

Command: ZOOM or Z

4. Type one of the following zoom options.

Specify corner of window, enter a scale factor (nX or nXP), or

[All/Center/Dynamic/Extents/Previous/Scale/Window/Object] :

Here,

All zooms to display the entire drawing in the current viewport. In a 3D view, ZOOM All is equivalent to ZOOM Extents. The display shows all objects even if the drawing extends outside the grid limits.

Center Specifies the center point and new display height.

Dynamic Displays the generated portion of the drawing with a view box. The view box represents your viewport, which you can enlarge or shrink and move around the drawing.

Extents Display the current drawing content as large as possible.

Previous It zooms to display the previous view. You can restore the previous view up to 10 previous views.

Scale It zooms the display at a specified scale factor.

Window Displays an area specified by two opposite corners of a rectangular window selection.

Specify first corner: point (1)

Specify opposite corner: point (2)

Object Displays one or more selected objects as large as possible and in the center of the drawing area. You can select objects before or after you start the ZOOM command.

Pan Command:

This command can be used to reposition the current drawing view in the drawing area. By holding the pan you can move not only the drawing objects but the entire drawing area along with the drawing objects.

In short, it shifts the location of a view.

1. Click on the PAN icon.

or

2. Choose View (on the menu bar), Pan

or

3. Type PAN (at the command prompt)

Command: PAN or P

Redraw Command:

It refreshes the current view. When BLIPMODE is on, marker blips are left on the drawing area by editing commands. These blips (dot-like structures) can be removed from the current viewport by using REDRAW command.

Marker Blips showed:

Marker Blips removed after REDRAW:

Blip mode:

It controls the display of marker blips on the drawing viewport. When the BLIP mode is ON, a temporary plus sign(+) shaped mark appears where points are specified.

1. Type BLIPMODE (on the command line)

Command: BLIPMODE

2. Type ON or OFF

Enter mode [ON/OFF] : (on/ off)

REGEN Command:

It regenerates the entire drawing objects. Display performance is improved when wide polylines and donuts, hatches, gradient fills, and text are displayed in a simplified form.

For instance:

If you draw a very small circle on your graphics screen and then zoom it to enlarge, you will see that the circle becomes like a polygon with a finite number of sides. In this case, you can use REGEN command to regenerate the actual shape of the circle.

Before REGEN:

After REGEN:

List Commands:

You can view the information about all what you command in the text window using this command. The text window displays the object layer, object type, and X,Y,Z position relative to the current user coordinate system (UCS)

1. Type LIST or LI on the command line

Command: LINE or LI

2. Pick the object/s to list

Select objects: (select with pick box)

3. Press ENTER when you are finished choosing the object/s.

4.5 Creating Isometric Drawing

Isometric Cursor:

1. Choose Tools (on the menu bar), Drawing Aids

or

2. Type DDRMODES on the command lines

Command: DDRMODES

3. Toggle Isometric Snap/Grid to ON.

Isoplane Toggle:

1. Press Function key F5 to toggle

<isoplane top>

<isoplane left>

<isoplane right>

2. Press 'Ctrl + E' to toggle the isoplanes

Isometric Circles :

1. Type ELLIPSE on the command line

Command: ELLIPSE or EL

2. Type Isocircle

Specify axis endpoint of ellipse or [Arc/Center/Isocircle]: isocircle

3. Type the center of isocircle

Specify center of isocircle: number, number

4. Type the radius or diameter of isocircle

Specify radius of isocircle or [Diameter]:

Isometric Text:

First of all, create two styles. Use oblique angle 30 degree for one style and -30 degree for the other.

Now, place your text (single or multi-line), change the rotation to 30 degree or -30 degree. It depends on where you want to put it.

Specify the rotation angle of text : -30

Try to create it with several style and text angle combination. Well, basically these three are all you need.

Isometric Dimensions:

Use command "DIMALIGNED "(i.e. aligned dimension) to provide the dimensions.

1. Type DIMALI to place an aligned dimensions
2. Type DIMEDIT oblique the angle of the dimension line and rotate the text.

Oblique Angle= -30

Rotated Angle= +30