AutoCAD

 

 

 

 

 

 

 

Background

Usage

Keys

Pointing

Screen

Drawing Commands

Snapping

Background

 

 

Published by Autodesk, Inc.

Currently at release 12

Initially designed as an architectural/engineering tool

Release 11 added a lot of 3-D modeling useful for manufacturing and CAM

Release 12 improves the user interface and allows AutoCAD to be run from Windows

Create much more than a drawing

Database contains precise information about

locations

sizes

colors

attributes

Allows you to

create reports

generate bills of material

generate numerical control data

MMSE AutoCAD Systems

 

 

Located in MMSE lab area, basement, Loras Hall, Room 6

Door to the Room 6 CAD/CAM lab is kept locked

Available 7 A.M. to Midnight, 7 days/week

working hours via walk-in (roughly 7 A.M. to 6 P.M.) - ask student workers or MMSE office staff on first floor for access

after hours via security, call 647-5100 or go to security offices at 2097 Grand Ave.

reservation book available, call 647-5566

a certain limited number of hours are blocked out for class demonstrations, which have priority for exclusive lab use

Need to produce a student ID and be registered for the course to have access to the CAD/CAM lab

If leaving after 6 P.M., call security to let them know you are leaving and lock up

Five machines are available, with slightly different configurations:

PC #5

Zeos 486

DOS 5.0

200 MB Hard disk drive

8 MB main memory

Microsoft 2 button Mouse

Shared LaserJet II printer

AutoCAD version 10 and NC-Auto-Code

AutoCAD version 12

DOSShell installed, run at startup

PC #10

IBM PS/2 Model 80

DOS 5.0

110 MB Hard disk drive

4 MB main memory

SummaSketch II Plus Tablet

Shared LasetJet II printer

AutoCAD version 12

DOSShell installed, run at startup

PC #31

Gateway 2000 486DX/33

DOS 5.0

200 MB Hard disk drive

8 MB main memory

Microsoft 2 button Mouse

HP PaintJet color ink printer

AutoCAD version 12

DOS prompt at startup

PC #32

Gateway 2000 486DX/33

DOS 5.0

200 MB Hard disk drive

8 MB main memory

Microsoft 2 button Mouse

Shared LaserJet II printer

AutoCAD version 12

DOS prompt at startup

PC #33

Gateway 2000 486DX/33

DOS 5.0

200 MB Hard disk drive

8 MB main memory

Microsoft 2 button Mouse

DOSShell installed, run at startup

(AutoCAD not installed yet, no hard copy device yet)

Starting AutoCAD

 

 

1. Turn on system unit

Push botton on right of system unit #5,31,32,33

Switch on upper area of system unit #10

2. Turn on monitor

Push yellow button on front of unit #5

Orange switch on side of unit #10

Switch on right rear of units #31,32,33

3. a. Enter at the DOS C:> prompt the command

acadr12

or

3. b. Select AutoCAD Release 12 from the DOSShell main menu

4. You will then be placed in the AutoCAD Release 12 drawing editor.

AutoCAD Main Menu (Versions 10 and 11)

 

 

0. Exit AutoCAD

returns to DOS

(QUIT command in version 12)

1. Begin a NEW drawing

will prompt you to enter NAME of drawing

wants a name of 1 to 8 characters - use initials and (part of) last name to keep names unique - or preface with a drive letter to work from a floppy

gives you a .DWG file

(NEW command in version 12)

2. Edit an EXISTING drawing

enter NAME of drawing

will show name of last file edited as the default

press return to get the default

(OPEN command in version 12)

3. Plot a drawing

answer questions, make sure plotter is connected and on

(PLOT command in version 12)

4. Printer Plot a drawing

answer questions, make sure printer is on

hit return if you don't know the answer to the question, because the default will usually work

possible exception to this rule is the question of scaling to fit to get exact scale, do not scale to fit, use a scale of 1 = 1

(PLOT command in version 12)

 

5. Configure AutoCAD

changes the behavior of AutoCAD

(CONFIG command in version 12)

6. File Utilities

list drawing files; delete, rename, and copy files

(FILES command in version 12)

7. Compile shape/font description file

(COMPILE command in version 12)

8. Convert old drawing file

convert from an earlier release

can convert from version 10 to version 11, but not back again

(OPEN command in version 12 automatically converts to version 11/12 format, which can then be used only in versions 11 and 12. Consult manual if converting files from versions 2.5 and earlier)

9. Recover damaged drawing

available only in versions 11 and 12

(RECOVER command in version 12)

 

Keyboard

 

 

Backspace

deletes character behind the character cursor

Del

deletes character in front of/under the character cursor

CTRL/X

deletes command

CTRL/C

cancels command (same as picking AutoCAD from menu)

F1

changes screen (drawing to text, back again)

F6

coordinates (off to on, on to off)

F7

grid (off to on, on to off)

F8

ortho (off to on, on to off)

F9

snap (off to on, on to off)

F10

tablet (off to on, on to off)

Pointing Device

(Selection Device)

 

 

Mouse

relative motion

can lift, repeat motion to move farther

2-Button Mouse

pick (select) with left button

return with right button

3-Button Mouse

pick (select) with leftmost button

assist with rightmost button

return with middle button

Puck

absolute motion

pick (select) with topmost button (yellow)

cancel with rightmost button (2nd row) (green)

return with leftmost button (2nd row) (white or red)

assist with bottommost button (blue)

AutoCAD Screen Layout

 

 

 

AutoCAD 10 Screen

 

 

 

AutoCAD 11 Screen

 

 

 

AutoCAD 12 Screen

 

 

 

AutoCAD 10 Screen with Menu Bar

 

 

 

AutoCAD 11 Screen with Menu Bar

 

 

 

AutoCAD 12 Screen with Menu Bar

 

 

 

GRID

 

The Grid command controls the display of a grid of dots to assist in the placement of objects in the drawing. The grid does not plot or print; it is only a reference for drawing ease.

Command:

GRID Grid spacing(X) orON/OFF/Snap/Aspect<current>:

Each of the options are described below:

Spacing(X)

A simple number sets grid spacing in drawing units. A number followed by "X" (i.e. 2X) sets the grid spacing to a multiple of the current SNAP setting. A value of 0 locks the grid spacing to the current SNAP setting

ON

Turns grid on with previous setting

OFF

Turns grid off

Snap

Locks the grid spacing to the current SNAP setting

Aspect

Permits a grid with different horizontal and vertical spacing

The grid can be turned on and off using the F7 function key. The grid, when on, fills up the drawing limits. The rotation and style of this visible grid will always match the rotation and style of the invisible snap.

SNAP

 

The "snap resolution" is the spacing of an imaginary grid with which newly designated points must align. The Snap command allows you to change the SNAP setting or to turn it off entirely.

Command:

SNAP Snap spacing ON/OFF/Aspect/Rotate/Style<current>

Each of the options are described below:

Number

Set snap spacing (i.e. 1 sets the snap to 1 unit)

ON

Turns snap on to align with designated setting

OFF

Turns snap off

Rotate

Rotate snap grid by specified angle, and allows you to set a specific base point for the grid

Aspect

Set different X/Y snap setting

Style ISO

Sets snap to isometric setting

The Snap can be turned on and off by using the F9 function key

Limits vs. Extents

 

 

Imaginary X-Y-Z coordinate system has no limits

In 2-D drafting, imagine the size of the sheet of drafting paper you decide to use as the drawing LIMITS

After several objects have been drawn, imagine the smallest rectangle that will fully enclose what you have drawn as the drawing EXTENTS

It is possible to create an object beyond the drawing LIMITS.

At startup, limits default to lower left = 0,0; upper right = 12, 9

Status command shows limits, snap setting, ortho setting, and numerous other environmental settings - places these on the text screen - press F1 to return to drawing screen

LIMITS

 

 

The Limits command allows you to change the upper and lower limits of the drawing area while working on a drawing, and to turn limits checking on or off.

Command:

LIMITS ON/OFF/<Lower left corner><current>:

Upper right corner<current>:

Each of the options are described below:

ON

Turns limit checking on so you cannot pick a point outside of the drawing limits

OFF

Turns limit checking off

Lower left corner

Changes the lower left corner coordinates

Upper right corner

Changes the upper right corner coordinates

When the limits have been changed, you must do a Zoom All to have the entire drawing displayed on your screen

Points

 

 

Whenever you work with points, lines, arcs, circles, limits, etc. in a drawing, you will need to enter points (or coordinates) to define a location on the drawing.

Points can be entered in the following ways:

1. Using the pointing device

pick with mouse (left button) or puck (top button)

2. Via keyboard entry

2.a. Absolute

x, y

2. b. Relative

@x_dist, y_dist

@dist < angle

Typically distances, points, and angles are entered as decimal numbers (or in scientific notation if very large or very small)

You can use the Units command to specify linear values in terms of feet and inches, or angles in terms of degrees/minutes/seconds, or grads, or radians

Drawing Screen Cursors

 

 

Cross Hairs (intersecting lines)

Obtain exact point of intersection when picked. May not have any relationship to any entity on the screen

Default when a point is expected

Pick Box (square box)

Obtain the entity crossing this box (or the most recently created entity)

Default when an entity is expected

Selection Box (square box with intersecting lines)

Obtain the entity crossing this box (or the entity closest to the center of the box)

Appears when "object snap" is used as a drawing aid

Window (dotted rectangle)

Obtain all entities entirely contained within the rectangle

Appears by "dragging" cursor with pick button from one corner to diagonally opposite corner

 

Units

 

 

Each drawing unit can represent any desired form of measurement, and need not be specified

Each drawing can be scaled to any scale at the time it is printed

It is possible to enter/display coordinates in these formats:

16.5 decimal (the default)

1.65E+01 scientific notation

1'4-1/2 architectural

1'4.5 engineering

16-1/2 fractional

In architectural and engineering formats, note the following:

16 always means 16 inches, never 16 feet

you can refer to decimal feet, as in 1.3'

In architectural and fractional formats, note the following:

improper fractions are not allowed with whole numbers

It is possible to enter/display angles in these formats:

30.0 decimal degrees (the default)

30d0'00" degrees/minutes/seconds

33.3333g grads

.5236r radians

N60d0'0"E surveyor's units

LINE

 

 

The Line command draws straight line segments. You can enter 2D or 3D points at the from point and to point prompts

At the from prompt, you can

- enter a point using any method discussed above

- use the drawing tools (osnaps) discussed below

- select continue or press return to start at the endpoint of the most recently drawn line

At the to prompt, you can

- enter a point using any method discussed above

- use the drawing tools (osnaps) discussed below

- enter C or close to close the line segments created during the command, connecting the starting point to the ending point

- enter U or undo to remove (undo) the last line, returning you to the previous endpoint

Example - Drawing a Box

 

Problem:

We want to draw a box, 6 inches wide, 4 inches high, with the lower left corner at the point 1,2.5

Solution 1:

Line

1,2.5

7,2.5

7,6.5

1,6.5

1,2.5

Solution 2:

Line

1,2.5

7,2.5

7,6.5

1,6.5

close

Solution 3:

Line

1,2.5

@6,0

@0,4

@-6,0

close

Solution 4:

Line

1,2.5

@6<0

@4<90

@6<180

@4<270

Object Snap

(OSnap Drawing Tool)

 

 

Many times you want to automatically identify a specific point in your drawing relative to an object you have already drawn. This might be the endpoint of a line, the center of a circle, or the tangent angle to a curve. In AutoCAD the feature is called "Object Snap" or "OSnap."

Use the OSNAP command to set the "running" object snap mode. (You can override the running mode for any particular point by pulling down the tools/assist menu)

When OSNAP is turned on (to start with it is turned off), the cursor changes to a box with crosshair.

The crosshairs do not have to lie exactly on the desired point.

- The target box needs to touch or contain part of the object

- The OSNAP mode has to be appropriately set

- You need to be closer to the desired point than any other point in the drawing that meeting the currently set OSNAP criterion

OSNAP Modes

 

 

CENter

CEN

Center of Arc or Circle

ENDpoint

END

Endpoint of Line

INSert

INS

Insertion point of Text/Block/Shape/Attribute

INTersec

INT

Intersection of Lines/Arcs/Circles

MIDpoint

MID

Midpoint of Line/Arc

NEArest

NEA

Nearest point on Line/Arc/Circle/Point

NODe

NOD

Nearest Point entity (or Dimension definition point)

PERpend

PER

Perpendicular to Line/Arc/Circle

QUAdrant

QUA

Quadrant point of Arc or Circle

QUICK

QUICK

Quick mode (first point that meets Osnap criteria)

TANgent

TAN

Tangent to Arc or Circle

NONE

NONE

Turns present Osnap mode off

 

 

Object Snap Modes

 

 

 

 

ARC

 

 

This command draws any segment of a circle in a variety of ways

First, you can begin with either the starting point of the arc or the center of the arc (default is starting point)

If you began with a starting point, you may continue with either a second point of the arc, the center of the arc, or the end of the arc (default is second point of the arc)

If you continued with a second point, you must continue with the end point of the arc. (3 point)

If you continued with the center of the arc, you may continue with the end point of the arc (SCE), the angle of the arc (SCA) (positive angles are counterclockwise), or the length of the chord (SCL) (default is end point of the arc)

If you continued with the end of the arc, you may continue with the angle of the arc (SEA), the radius of the arc (SER), or the direction of the tangent line at the start of the arc (SED) (default is the angle of the arc)

If you began with the center point, you must continue with the start point of the arc. After the start point of the arc, you must conclude with the endpoint of the arc (SCE), the angle of the arc (SCA), or the length of the chord (SCL) (default is the endpoint of the arc)

 

ARC Drawing Options

 

 

 

 

CIRCLE

 

 

This command draws circles. The default method of drawing a circle is to specify a center point and a radius.

If you start by specifying the center point, you have the option of continuing with either the radius or the diameter

You can also draw circles via three other methods

- 3-point method

specify three points on the circumference

- 2-point method

specify two points which indicate the endpoints of the diameter

- TTR (tangent-tangent-radius)

specify two points on an existing line, circle, or arc that will be tangent to the newly formed circle, and then specify the length of the radius

CIRCLE Drawing Options

 

 

 

 

ELLIPSE

 

 

The Ellipse command, not found on the pull-down menu, also provides several methods for making ellipses. Ellipses are specified by their major and minor axes. You can start with either one.

The default method is to specify the endpoints of one axis, and then to specify the length of the other axis

After defining the endpoints of one (the major) axis, you could also continue by specifying the rotation around this major axis (between 0 degrees for a flat line and 89.4 degrees)

You can also start with specifying the center point of the ellipse, and then follow that with one endpoint for each of the two minor/major axes