autocad basic commands.pdf

7/27/2019 AutoCad basic commands.pdf

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National University of Singapore

Department of Civil Engineering----------------------------------

CE2408: Computed Aided Engineering

Semester 1, 07/08

Laboratory Reference Guide

BASIC COMMANDS OF AUTOCAD


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CE 2408 Computer Aided Engineering Semester 1, 07/08

Introduction

AutoCAD is popular CAD (Computer-Aided Design) software product for 2- and 3-dimensional design

and drafting, developed and sold by Autodesk. It is used extensively by civil and mechanical engineers,

interior designers and other design professionals, who seek to translate and present their works and ideas.

AutoCAD is fundamentally a vector graphics drawing program. It uses primitive entities such as lines,

polylines, circles, arcs, and text as the foundation for more complex objects.

The AutoCAD graphics window

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Drawing Objects

1. Units And Scales

As a general rule, everything you draw with AutoCAD will be drawn full size. In AutoCAD you do not

need to decide upon a drawing scale (1:20, 1:100 etc) until you come to print the drawing and because the

scaling of your drawing takes place at the printing stage, you can create drawings at a scale of 1:1.

Other then scaling, the user must decide what units you will use before you start drawing. One drawing

unit could represent one millimetre, one centimetre, one metre, one inch, one foot etc. In structural

element representation, engineer usually work with mm while in the overall structural design, we would

definitely work in metres.

Units Control

Tool Bar None

Pull Down Format > Units

Keyboard UNITS

"Length" which refers

to linear units

"Angle" which refers to

angular units

Insertion Scale

allows users to assign

specific unit to the

drawing

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Length Type

Unit Type 1.5 Drawing Units 1500 Drawing Units Description

Decimal 1.5000 1500.0000 Metric or SI units

Scientific 1.5000E+00 1.5000E+03 Decimal value raised toa power

Engineering 0'-1.5000" 125'-0.0000" Feet and decimal inches

Architectural 0'-1 1/2" 125'-0"Feet and fractional

inches

Fractional 1 1/2 1500Whole numbers and

fractions

Angle Type

Unit Type 12.5 Angular Units 180 Angular Units Description

Decimal Degrees 12.500 180.000 Metric units

Deg/Min/Sec 12d30'0" 180d0'0"Degrees, Minutes and

Seconds

Grads 13.889g 200.000g 400 grads = 360 degrees

Radians 0.218r 3.142r2 Pi radians = 360

degrees

Surveyor N 77d30'0" E W Compass bearings

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2. Drawing Functions

In AutoCAD, the most primary commands are the Draw commands. These commands can be accessed

through the function pull-down menu Draw at the top of the window or the Draw QuickFind toolbar

as seen in the figure below.

2.1 Lines

Lines are probably the most simple of AutoCAD objects. Using the Line command, a line can be drawn

between any two points picked within the drawing area. The drawn lines are known as vectors and that

explains the fact that AutoCAD is known as a vector graphics drawings program.

The Line Command: With the Line command you can draw a simple line from one point to another.

When youpickthe first point and move the cross-hairs to the location of the second point you will see a

rubber band line which shows you where the line will be drawn when the second point is picked. The

length and the angle of inclination of the line can be specified after choosing the initial point. Tab is used

to toggle between the parameters.

Tool Bar

Pull Down Draw > LineKeyboard LINE or L

Command

Sequence

Command: LINE

Speci f y f i rst poi nt : (pick P1)

Speci f y next poi nt or [ Undo]: (pick P2) / Specify length and angle

Speci f y next poi nt or [ Undo]: (to end)

The Construction Line Command: The Construction Line command creates a line of infinite length

which passes through two picked points. Construction lines are very useful for creating construction

frameworks or grids within which to design. They are usually not kept in the final product as their main

purpose is to aid the user in the drawing process.

The "Hor" and "Ver" options can be used to draw construction lines that are purely horizontal or vertical.

Tool Bar

Pull Down Draw > Construction Line

Keyboard XLINE or XL

Command

Sequence

Command: XLINE

Speci f y a poi nt or [ Hor / Ver / Ang/ Bi sect/ Of f set ] : (pick a point)

Speci f y t hr ough poi nt : (pick a second point)

Speci f y t hr ough poi nt : (to end or pick another point)

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The Ray Command: The Ray command creates a line similar to a construction line except that it extends

infinitely in just one direction from the first pick point.

Tool Bar

Pull Down Draw > Ray

Keyboard RAYCommand

Sequence

Command: RAY

Speci f y star t poi nt : (pick the start point)

Speci f y t hr ough poi nt : (pick a second point to determine direction)

Speci f y t hr ough poi nt : (to end or pick another point)

2.2 The polyline family

Polylines differ from lines in that they are more complex objects. Polylines are made up of a number of

straight-line or arc segments. Line widths can be edited to make them appear solid.

The Polyline Command: The Polyline or Pline command is similar to the line command except that the

resulting object may be composed of a number of segments which form a single object. C can be used to

close option instead of hitting or connecting two ends of the polyline. Follow the command sequence

below to see how this works.

Tool Bar

Pull Down Draw > Polyline

Keyboard PLINE/PL

CommandSequence

Command: PLINESpeci f y star t poi nt : (pick P1)

Cur r ent l i ne- wi dt h i s 0. 0000

Speci f y next poi nt or [ Ar c/ Hal f wi dt h/ Lengt h/ Undo/ Wi dt h] : (pick P2)

Speci f y next poi nt or [ Ar c/ Cl ose/ / Wi dt h] : (pick P3)

Speci f y next poi nt or [ Ar c/ Cl ose/ / Wi dt h] : (pick P4)

Speci f y next poi nt or [ Ar c/ Cl ose/ / Wi dt h] : (or C to close)

The Rectangle Command: The Rectangle command is used to draw rectangles with vertical and

horizontal lines. The rectangle is defined by two extreme corners defined by the user.

Tool Bar

Pull Down Draw > Rectangle

Keyboard RECTANGLE/REC

Command

Sequence

Command: RECTANG

Speci f y f i r st cor ner poi nt or

[ Chamf er / El evat i on/ Fi l l et / Thi ckness/ Wi dt h] : (pick P1)

Speci f y other cor ner poi nt or [ Di mensi ons] : (pick P2)

Chamfer, Elevation, Fillet, Thickness and Width are options that the user can specify to modify the shapeof the rectangular. The user can also input the dimensions of the rectangle instead of choosing a second

point.

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The Polygon Command: The Polygon command can be used to draw any regular polygon from 3 sides

up to 1024 sides. This command requires four inputs from the user, the number of sides, a pick point for

the centre of the polygon, whether you want the polygon inscribedorcircumscribed(see figure below)

and a pick point which determines both the radius of this imaginary circle and the orientation of the

polygon. The polygon command creates a closed polyline in the shape of the required polygon.

Tool Bar

Pull Down Draw > Polygon

Keyboard POLYGON/POL

Command

Sequence

Command: POLYGON

Ent er number of si des : 5

Speci f y cent er of pol ygon or [ Edge]: (pick P1 or type E to define by edge

length)

Ent er an opt i on [ I nscri bed i n ci r cl e/ Ci r cumscri bed about ci r cl e]

: (Inscribed if not specified)

Speci f y r adi us of ci r cl e:(pick P2 or enter exact radius)

The Donut Command: This command allows user to create a solid donut shape. The diameter of the

hole i.e. inner diameter and the outside diameter of the donut are required.

Tool Bar

Pull Down Draw > Donut

Keyboard DONUT/DO

Command

Sequence

Command: DONUT

Speci f y i nsi de di ameter of donut : (pick any two points to define a

diameter or enter the exact length)

Speci f y outsi de di amet er of donut : (pick any two points to define a

diameter or enter the exact length)

Speci f y cent er of donut or : (pick P1)

Speci f y cent er of donut or : (to end or continue to pick for more

doughnuts)

2.3 Circles, Arcs etc

Along with Line and Polyline, the Circle command is probably one of the most frequently used.

Fortunately it is also one of the simplest. However, in common with the other commands in this sectionthere are a number of options that can help you construct just the circle you need. Most of these options

are self explanatory but in some cases it can be quite confusing. The Circle command, for example, offers

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6 ways to create a circle, while the Arc command offers 10 different methods for drawing an arc. The

sections below concentrate mainly on the defaultoptions but feel free to experiment.

The Circle Command: The Circle command is used to draw circles. There are a number of ways you can

define the circle. The default method is to pick the centre point and then to either pick a second point to

specify the radius. Alternatively, you can enter the exact dimension of the diameter. The option 3P allowsusers to draw a circle with 3 points on the circumference. The other option (tan tan radius/ttr) enables us

to draw a circle whose circumference is tangential to two other lines.

Tool Bar

Pull Down Draw > Circle > Centre, Radius

Keyboard CIRCLE/C

Command

Sequence

Command: CIRCLE

Speci f y cent er poi nt f or ci r cl e or [ 3P/ 2P/ Tt r ( t an t an radi us)] :

(pick P1)

Speci f y radi us of ci r cl e or [ Di ameter ] : (pick P2 or enter the exact

radius)

The Arc Command: The Arc command allows you to draw an arc of a circle. The default method uses

three pick points (a start point, a second point and an end point).

Tool Bar

Pull Down Draw > Arc > 3 Points

Keyboard ARC/A

The Ellipse Command: The Ellipse command gives you a number of different creation options. The

default option is to pick the two end points of an axis and then a third point to define the shape of the

ellipse.

Tool Bar

Pull Down Draw > Ellipse > Axis, End

Keyboard ELLIPSE/EL

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The Spline Command: A spline is a smooth curve that is fitted along a number of control points. The Fit

Tolerance option is used to control how closely the spline conforms to the specified control points. The

illustration on the right shows the effect of various tolerance values on a spline that is defined using the

same four control points. The default tolerance setting is zero.

Tool Bar

Pull Down Draw > Spline

Keyboard SPLINE/SPL

Command

Sequence

Command: SPLINE

Speci f y f i r st poi nt or [ Obj ect] : (Pick P1)

Speci f y next poi nt : (Pick P2)

Speci f y next poi nt or [ Cl ose/ Fi t t ol er ance] : (Pick P3)

Speci f y next poi nt or [ Cl ose/ Fi t t ol er ance] :

Speci f y st ar t t angent : (pick a point)

Speci f y end t angent : (pick a point)

2.4 Multi-linesMulti-lines are complex lines that consist of between 1 and 16 parallel lines which are drawn

simultaneously. The default multiline style has just two elements (lines) but you can create additional

lines and styles by editing this feature.

The Multi-line Command: The Multiline command is used to draw multilines. This process of drawing

is pretty much the same as drawing polylines, additional line segments are added to the multiline as points

are picked. As with polylines, points can be unpicked with the Undo option and multilines can be closed.

When Multiline command is activated, the users have to specify the 3 parameters: Justification, Scale and

Style. The Justification option is set to "Top" in default. When Top is chosen, the top line will be the

guide for the other lines. Zero justification guides the drawing through the centreline and Bottom draws

the bottom line through the pick points. The Figure Below illustrates an example of a multiline with Top

justification.

The Scale option allows you to set a scale factor, which effectively changes the width of the multiline.

The default scale factor is set to 1.0

The Style option enables you to set the current multiline style. The default style is called "Standard". The

style can be changed through the command Format > Multiline Style.

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Tool Bar

Pull Down Draw > Multiline

Keyboard MLINE/ML

Command

Sequence

Command: MLINE

Cur r ent set t i ngs: J ust i f i cat i on = Top, Scal e = 1. 00, St yl e =

STANDARD

Speci f y start poi nt or [ J ust i f i cat i on/ Scal e/ St yl e] : (Pick P1)

Speci f y next poi nt : (Pick P2)

Speci f y next poi nt or [ Undo]: (Pick P3)

Speci f y next poi nt or [ Cl ose/ Undo] : (to end or continue picking or C to

close)

2.5 Hatch

Hatching in AutoCAD is a way of filling in areas of your drawing with a pre-formatted pattern torepresent certain materials. It is usually used in sectional views. Starting with AutoCAD release 14, you

can use a solid fill to completely fill in areas such as walls in a floor plan.

There are two types of hatching you can use. Generally you will want use the BOUNDARY HATCH

command.

Tool Bar

Pull Down Draw > Hatch

Keyboard BHATCH/H

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Upon initiating the Hatch command, the dialog box below will be displayed.

Select Objects for hatching

Select desired

surface design

Hatching

conforms to

changes in the

form of the object

The existing hatch can be modified through the hatch edit command as below.

Tool Bar

Pull Down Modify > Object > Hatch

Keyboard BHATCH/H

2.5 Text

Short labels and comments are essential in most engineering drawings. Single-line text is usually

employed as separate objects. There is also multiline text.

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Single Line Text:

Tool Bar None

Pull Down Draw > Text > Single Line Text

Keyboard TEXTCommand

Sequence

Command: TEXT

Cur r ent t ext st yl e: "St andar d" Text hei ght : 0. 2000

Speci f y start poi nt of t ext or [ J ust i f y/ St yl e] : Pick a start point for the

text

Speci f y hei ght : Type a height, or press Enter to accept the default height

Speci f y rot ati on angl e of t ext : Specify the inclination of the text, or press

Enter to accept the default angle

Enter text and press Enter to end

Multiline Text:

Tool Bar

Pull Down Draw > Text > Multiline Text

Keyboard MTEXT

Command

Sequence

Command: MTEXT

Cur r ent t ext st yl e: "St andar d" Text hei ght : 3. 2887

Speci f y f i r st cor ner : Specify the left corner of the text

Speci f y opposi t e cor ner or [ Hei ght / J usti f y/ Li nespaci ng/ Rot at i on/ St yl e/ Wi dt h] : Specify the size of the textbox

Enter text and press OK to end

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MODIFYING OBJECTS

AutoCAD provides a whole range of modify tools such as Move, Copy, Rotate and Mirror among many

to manipulate the drawings. Similar to the drawing functions, the Modifying functions/tools can be

accessed by the Pulldown menu or the QuickFind toolbar below.

The Erase Command: The Erase command deletes any selected object(s) from the drawing.

Tool Bar

Pull Down Modify > Erase

Keyboard ERASE/E

Command

Sequence

Command: ERASE

Sel ect obj ects: (pick an object to erase)

Sel ect obj ects: (to end the selection and erase the object)

The Copy Command: The Copy command can be used to create duplicates of any drawing object or

objects which you have previously created. The copy process requires 3 points. The first point P1 will

indicate the object to copy. The other 2 points are the "Base point", P2 and the "Second point"; the twopoints are simply used to indicate the distance and direction of the copied object from the original object.

Tool Bar

Pull Down Modify > Copy

Keyboard COPY/CP

Command

Sequence

Command: COPY

Sel ect obj ects: (pick object to copy, P1)

Sel ect obj ects: (to end selection)

Speci f y base poi nt or di spl acement , or [ Mul t i pl e] : (pick P2 or M for

multiple copies)

Speci f y second poi nt of di spl acement or : (pick P3)

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The Mirror Command: The Mirror command allows the user to reflect selected objects in the drawing

by picking them and then defining the position of an imaginary mirror line using two points (as seen in

the figure below).

Tool Bar

Pull Down Modify > Mirror

Keyboard MIRROR

Command

Sequence

Command: MIRROR

Sel ect obj ects: (pick object to mirror, P1)


Speci f y f i rst poi nt of mi rr or l i ne: (pick P2)

Speci f y second poi nt of mi r r or l i ne: (pick P3)

Del et e source obj ect s? [ Yes/ No] : (for No to keep the original object)

The Offset Command: The Offset command creates a new object parallel to or concentric with a

selected object. The new object is drawn at a user defined distance (the offset) from the original and in a

direction chosen by the user with a pick point. The illustration below demonstrates the effects of the

offset command.

Tool Bar

Pull Down Modify > Offset

Keyboard OFFSET

Command

Sequence

Command: OFFSET

Speci f y of f set di st ance or [ Thr ough] : (specify distance)

Sel ect obj ect t o of f set or : (select object, P1)

Speci f y poi nt on si de t o of f set : (pick direction, P2)Sel ect obj ect t o of f set or : (to end or select another object to offset)

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The Array Command: The Array command makes multiple copies of selected objects in a rectangular

matrix or a polar pattern.

Tool Bar

Pull Down Modify > Array

Keyboard ARRAY

The Rectangular Array: The illustration on the right shows the results

of a rectangular array with two columns and three rows. The distance

between rows is indicated with the dimension DR and between columns

with DC. When creating rectangular arrays it is important to remember

that new rows are created above the original object and new columns are

created to the right of the original object. The resulting array is, therefore,

always created with the original object in the bottom left hand position

with respect to the current co-ordinate system

The window above controls the parameters which will formulate the rectangular array.

1. Choose Rectangular Array.

2. Click the Select objects button and choose the object which the array will be based on. Press the

Return button on your keyboard to complete the selection.

3. Enter the number of rows required in the Rows edit box.

4. Enter the number of columns required in the Columns edit box.

5. Enter the row offset in the Row Offset edit box. This is the distance DR in the illustration above. Note

that this is NOT the distance between rows. It is more appropriate to describe it as the distance

between the same points of the objects.

6. Enter the column offset in the Column Offset edit box. The same parameters apply as for the row

offset.

7. Click on the Preview button. Once again, the dialogue box disappears and the specified array is

temporarily drawn so that we can preview it. We are now offered 3 choices. If the array isn't quite

right, click the Modify button to return to the Array dialogue box. If you are happy with the array,

click the Accept button, the array will be permanently drawn and the command is ended.

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The Polar Array: The polar array works in a similar way to the rectangular array. The main difference is

that rather than specifying the number and offset for rows and columns, you must specify a center point

and the total number of objects in the array (including the original object).

The window above controls the parameters which will formulate the Polar array.

1. Click the Select objects button as per the step in forming Rectangular array.

2. Specify the center point for the array. The user can either input the coordinates of the centre of the

array or pick the centre on the drawing.

3. Enter a value for the total number of items.

4. Determine whether the objects are to be rotated in the polar array. The difference is illustrated in the

figure below.

5. Click on the Preview button and verify if the array needs to be modified.

The Move Command: The Move command works in a similar way to the Move command except that

the original object will not remain in the original position.

Tool Bar

Pull Down Modify > Move

Keyboard MOVE/M

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The Rotate Command: The Rotate command allows an object or objects to be rotated about a point

selected by the user. AutoCAD, by default, will start the angle at 3 o'clock and increase in an anti-

clockwise direction which is specified as ANGBASE and ANGDIR respectively. Clockwise rotation will

require a negative angle.

Tool Bar

Pull Down Modify > Rotate

Keyboard ROTATE/RO

Command

Sequence

Command: ROTATE

Cur r ent posi t i ve angl e i n UCS: ANGDI R=count er cl ockwi se ANGBASE=0

Sel ect obj ects: (pick object to rotate, P1)


Speci f y base poi nt : (pick base point, P2)

Speci f y rot at i on angl e or [ Ref er ence]: (pick second point, P3 or enter angle)

The Scale Command: The Scale command can be used to change the size of an object or group of

objects. The user is required to pick a point about which the selection set will be scaled. Scaling can then

be completed by picking a second point or by entering a scale factor at the keyboard.

Tool Bar

Pull Down Modify > Scale

Keyboard SCALE

CommandSequence

Command: SCALESel ect obj ects: (pick objects to be scaled, P1)


Speci f y base poi nt : (pick base point, P2)

Speci f y scal e f act or or [ Ref er ence] : (pick second point, P3 or enter scale factor)

The Stretch Command: The Stretch command can be used to move one or more vertices of an object

whilst leaving the rest of the object unchanged. In the example below, a rectangle has been stretched by

moving one vertex to create an irregular shape.

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Tool Bar

Pull Down Modify > Stretch

Keyboard STRETCH

Command

Sequence

Command: STRETCH

Sel ect obj ect s t o str et ch by crossi ng- wi ndow or crossi ng-pol ygon. . .

Sel ect obj ects: (pick first point of crossing window)

Speci f y opposi t e cor ner : (pick second point of window)


Speci f y base poi nt or di spl acement : (pick base point)

Speci f y second poi nt of di spl acement : (pick second point)

The Lengthen Command: The Lengthen command can be used to either lengthen or shorten Lines,

Arcs, open Polylines, elliptical Arcs and open Splines without the use of cutting or boundary edges. The

command sequence above demonstrates the use of the Dynamic DY Lengthen option which is probably

the most useful for general purpose drafting. The Total option allows you to change the total length of a

line to any value that you specify. The Percent option allows you to change a line length using a

percentage. The Delta option can be used to extend or reduce the endpoint of a line by a given distance.

Tool Bar

Pull Down Modify > Lengthen

Keyboard LENGTHEN

Command

Sequence

Command: LENGTHEN

Sel ect an obj ect or [ DEl t a/ Per cent / Tot al / DYnami c] : DYSel ect an obj ect t o change or [ Undo] : (select a line or arc)

Speci f y new end poi nt : (pick new end point)

Sel ect an obj ect t o change or [ Undo] : (to end)

The Trim Command: The Trim command can be used to trim/remove a part of an object. A "cutting

edge" is required in this command and it can take any form. The illustration below shows the Trim

command in action. The cutting edges are selected first (P1) and then the objects to be trimmed are

selected (P2 and P3

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Tool Bar

Pull Down Modify > Trim

Keyboard TRIM/TR

Command

Sequence

Command: TRIM

Curr ent set t i ngs: Proj ect i on=UCS Edge=NoneSel ect cut t i ng edges . . .

Sel ect obj ects: (select the cutting edge, P1)

Sel ect obj ects: (to end cutting edge selection)

Sel ect obj ect to t r i m or shi f t - sel ect to extend or

[ Proj ect / Edge/ Undo] : (pick the part of the square which you want to trim, P2)

Sel ect obj ect t o t r i m or shi f t - sel ect t o extend or

[ Proj ect / Edge/ Undo] : (pick the circle, P3)

Sel ect obj ect t o t r i m or shi f t - sel ect t o extend or

[ Proj ect / Edge/ Undo] : (to end)

The Extend Command: This command extends a line, polyline or arc to meet another drawing object

(known as the boundary edge). Three selections are made in the illustration below. Similar to the Trim

command, the edge is chosen first then the objects that are going to be extended. In order to determine the

direction in which the object is going to be extended, the user must click on the appropriate location on

the object. As seen the figure below, the line will be extended to the right if the use click on the right side

of the midpoint and vice versa.

In order to determine the direction in which the object is going to be extended, the user must click on the

appropriate location on the object. As seen the figure below, the line will be extended to the right if the

use click on the right side of the midpoint and vice versa.

If the line you are trying to extend does not intersect with the boundary line, you can use the "Edge"

option to toggle Edgemode to "Extend. This command is demonstrated in the figure below where the

endpoint of P2 is extended to be level with P1.

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Tool Bar

Pull Down Modify > Extend

Keyboard EXTEND

Command

Sequence

Command: EXTEND

Curr ent set t i ngs: Proj ect i on=UCS Edge=None

Sel ect boundary edges . . .

Sel ect obj ects: (select the boundary edge, P1)

Sel ect obj ects: (to end boundary edge selection)

Sel ect obj ect t o extend or shi f t - sel ect t o t r i m or

[ Proj ect / Edge/ Undo] : (pick the object which you want to be extended, P2)


[ Proj ect / Edge/ Undo] : (pick another object which you want to be extended, P3)


[ Proj ect / Edge/ Undo] : (to end)

The Break Command: The Break command enables you to break (remove part of) an object by defining

two break points. In the illustration below, a corner of a rectangle has been removed. When you break an

object, you can either select the object using the first break point and then pick the second break point, or

you can select the object and then pick the two break points.

Tool Bar

Pull Down Modify > Break

Keyboard BREAK

Command

Sequence

Command: BREAK

Sel ect obj ects: (select the object using the first break point, P1)

Speci f y second br eak poi nt or [ Fi r st poi nt ] : (pick the second break point,

P2)

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The Chamfer Command: The Chamfer command enables you to create a chamfer between any two

non-parallel lines as in the illustration below or any two adjacent polyline segments as seen I the figure

below.

Tool Bar

Pull Down Modify > Chamfer

Keyboard CHAMFER

Command

Sequence

Command: CHAMFER

( TRI M mode) Curr ent chamf er Di st 1 = 10. 0000, Di st 2 = 10. 0000

Sel ect f i r st l i ne or [ Pol yl i ne/ Di stance/ Angl e/ Tr i m/ Met hod] : D (to set

distances)

Speci f y f i r st chamf er di st ance : 20 (enter required distance)

Speci f y second chamf er di st ance : (first distance value or enter a

different value)

Sel ect f i r st l i ne or [ Pol yl i ne/ Di stance/ Angl e/ Tr i m/ Met hod] : (pick P1)

Sel ect second l i ne: (pick P2)

The Fillet Command: The Fillet command allows user to smoothen corners between two intersecting

lines (as seen in the figure below). The user would need to define the radius of the fillet and the lines

where the fillet is going to be formed.

Tool Bar

Pull Down Modify > Fillet

Keyboard FILLET

Command

Sequence

Command: FILLET

Curr ent set t i ngs: Mode = TRI M, Radi us = 10. 0000

Sel ect f i r st obj ect or [ Pol yl i ne/ Radi us/ Tr i m] : R

Speci f y f i l l et r adi us : 25

Sel ect f i r st obj ect or [ Pol yl i ne/ Radi us/ Tr i m] : (pick P1)Sel ect second obj ect : (pick P2)

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DRAWING AIDS

AutoCAD has drawing aids which can help you to draw horizontal and vertical lines on a computer. This

section will cover some of these functions.

Ortho Mode: Ortho is short fororthogonal, which means either vertical or horizontal. It can be found on

the status bar, Ortho is not a command, it is a drawing mode which can either be turned on or off. With

Ortho mode turned on you can only draw lines which are either vertical or horizontal

Tool Bar

Pull Down None

Keyboard Ortho/F8

Drawing Grid: The drawing grid is a regular pattern of dots displayed on the screen which acts as a

visual aid. The grid spacing can be controlled by the user as illustrated in the figure below.

Grid spacing set to 5 drawing units Grid spacing set 10 drawing units

The Snap option when activated allows users to connect endpoints with the grid points only. Users can

also change the aspect ration of the grid by changing the settings which can be accessed by right clicking

. More details will be covered in Drafting Setting.

Tool Bar

Pull Down None

Keyboard GRID/F7

Drawing Limits: Drawing Limits is used to define the extent of the grid display and to toggle Limits

mode which can be used to define the extent of your drawing. The grid is displayed within a rectangle

defined by two pick points or co-ordinates.

Tool Bar None

Pull Down Format > Drawing LimitsKeyboard LIMITS

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Snap Mode: Snap mode turned on AutoCAD only allows you to pick points which lie on a regular grid

as discussed in the previous paragraph. The Snap grid is completely independent of the display grid.

However, the Grid spacing and Snap spacing are usually set to the same value to avoid confusion. You

can force the display grid to conform to the snap grid by setting the display grid spacing to zero. The

display grid will then automatically change each time the snap grid is changed. More options of SNAP

will be covered the subsequent sections.

Tool Bar

Pull Down None

Keyboard SNAP/F9

Drafting Settings: The Snap and Grid mode settings, can also be made from the Drafting Settings

dialogue box, illustrated below

Tool Bar None

Pull Down Tools > Drafting Settings

Keyboard DDRMODES

.

If you are creating drawings in isometric projection, use the "Isometric snap" option to change the grids

from the standardorthogonal square grid to a 30 degree isometric grid.

`

Standard orthogonal grid Isometric grid

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Polar Tracking: Polar Tracking allows you to snap into whatever angles you choose to configure.

By default, Polar Tracking snaps only to the horizontal and the vertical. When you are drawing a line,

pick the first point and then move the cursor close to a vertical or horizontal location and your cursor will

snap into place. A polar tracking vector and a tool tip which displays the angle and the distance from the

pick point will be displayed.

Tool Bar

Pull Down None

Keyboard F10

The Increment angle drop-down list is used to set the preset angle increments. For example, if the

increment angle is set to 22.5 degrees, Polar Tracking will snap at 22.5 degree increments starting with

zero degrees. Alternatively, the user can set specific snap angles.

Object Snap: The Object Snaps (Osnaps for short) are drawing aids which are used in conjunction with

other commands to help you draw accurately. Osnaps allow you to snap onto a specific object location

when you are picking a point. The commands can be accessed through the Quickfind Toolbar.

Endpoint: The Endpoint Osnap snaps to the end points of lines and arcs and to polyline vertices.

Tool Bar

Pull Down NoneKeyboard END (while selecting objects)

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Midpoint: The Midpoint Osnap snaps to the mid pionts of lines and arcs and to the mid point of polyline

segments.

Tool Bar

Pull Down NoneKeyboard Mid (when picking)

Intersection: The Intersection Osnap snaps to the physical intersection of any two drawing objects (i.e.

where lines, arcs or circles etc. cross each other) and to Polyline vertices.

Tool Bar

Pull Down None

Keyboard INT (when picking)

Apparent Intersection: Apparent Intersection snaps to the point where objects appear to intersect in the

current view. For example, you may be looking at a drawing in plan view where two lines cross, as in the

illustration. However, since AutoCAD is a 3 dimensional drawing environment, the two lines may not

physically intersect. One line may be at ground level and the other may be 10 meters or more above or

below ground level.

Tool Bar

Pull Down NoneKeyboard APP/APPINT (when picking)

Extension: The Extension Osnap enables you to snap to some point along the imaginary extension of a

line, arc or polyline segment. To use this osnap, you must hover the cursor over the end of the line you

want to extend. When the line end is found, a small cross appears at the endpoint and a dashed extension

line is displayed from the endpoint to the cursor, providing the cursor remains close to the extension. The

Snap Tip for Extension also includes the relative polar co-ordinate of the current cursor position.

Tool Bar

Pull Down None

Keyboard EXT/EXTEN (when picking)

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Center: The Center Osnap snaps to the centre of a circle, arc or polyline arc segment. The cursor must

pass over the circumference of the circle or the arc so that the centre can be found. This often causes some

confusion for new users.

Tool BarPull Down None

Keyboard CEN (when picking)

Quadrant: The Quadrant Osnap snaps to one of the four circle quadrant points located at north, south,

east and west or 90, 270, 0 and 180 degrees respectively.

Tool Bar

Pull Down None

Keyboard QUA/QUAD (when picking)

Tangent: The Tangent Osnap snaps to a tangent point on a circle. This osnap works in two ways. You

can either draw a line from a point to the tangent point (see illustration) or you can draw a line from a

tangent point, the latter is referred to as the "Deferred Tangent" snap mode.

Tool BarPull Down None

Keyboard TAN (when picking)

Perpendicular: The Perpendicular Osnap snaps to a point which forms a perpendicular with the selected

object.

Tool Bar

Pull Down None

Keyboard PER/PERP (when picking)

Parallel: The Parallel Osnap is used to draw a line parallel to any other line

in your drawing. In operation, this osnap is slightly less intuitive than some of the others. To draw a

parallel line, first start the Line command, specify the first point when prompted and then start the Parallel

Osnap. Hover the cursor over an existing line until you see the Parallel snap marker. Now, move the

cursor close to a parallel

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position and a dotted line will appear, indicating the parallel. You can now pick the second point of your

line.

Tool Bar

Pull Down NoneKeyboard PAR/PARA (when picking)

Node: The Node Osnap snaps to the center of a Point object. This osnap can be useful if you have created

a number of Points with the Measure or Divide commands.

Tool Bar

Pull Down None

Keyboard NODE (when picking)

Nearest: The Nearest Osnap snaps to the nearest point on a drawing object. This Osnap is useful if you

want to make sure that a pick point lies on a drawing object but you don't necessarily mind exactly where

it is located.

Tool Bar

Pull Down None

Keyboard NEA/NEAR (when picking)

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DIMENSIONS

Dimensions are important parts of most drawings. Dimensions indicate the measurement of the models

that have been created. They aid the designer in communicating the proper size and shape of the models

to the manufacturer. The commands can be found either at the top of the window or they can be displayed

as a Quickfind Toolbar as shown below.

Linear Dimension: Used for dimensioning either horizontal or vertical distances.

Tool Bar

Pull Down Dimension > Linear

Keyboard DIMLINEAR

Command

Sequence

Command: DI MLI NEAR

Speci f y f i r st extensi on l i ne or i gi n or : (pick starting

point of the object to measure)

Speci f y second extensi on l i ne or i gi n:(pick end point of the object)

Speci f y di mensi on l i ne l ocat i on or

[ Mt ext / Text / Angl e/ Hor i zont al / Ver t i cal / Rot at ed] : ( Specify the location of

the dimension and other parameters such as multiline text, text style, inclination of text)

Aligned Dimension: Measure the actual length of an angled line.

Tool Bar

Pull Down Dimension > Aligned

Keyboard DIMALIGNED

Command

Sequence

Command: DIMADLIGNED

Speci f y f i r st extensi on l i ne or i gi n or : (pick starting

point of the object to measure)

Speci f y second extensi on l i ne or i gi n: (pick end point of the object)

Speci f y di mensi on l i ne l ocat i on or

[ Mt ext/ Text/ Angl e] : ( Specify the location of the dimension and other parameters such

as multiline text, text style, inclination of text)

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Arc Length: Measure the length of an arc

Tool Bar

Pull Down Dimension > Arc Length

Keyboard DIMARCCommand

Sequence

Command: DI MARC

Sel ect arc or pol yl i ne arc segment : (pick object to measure)

Speci f y ar c l engt h di mensi on l ocat i on, or

[ Mt ext / Text / Angl e/ Par t i al / Leader ] : ( Specify the location of the dimension and

other parameters such as multiline text, text style, inclination of text)

Ordinate: Used in mechanical drawings as it labels the X and Y coordinates based on a 0,0 coordinate

placed somewhere on the model.

Tool Bar

Pull Down Dimension > Ordinate

Keyboard DIMORDINATE

Radius: Measures the radius of circles and arcs

Tool Bar

Pull Down Dimension > Radius

Keyboard DIMRADIUSCommand

Sequence

Command: DI MRADI US

Sel ect ar c or ci r cl e: (pick object to measure)

Speci f y di mensi on l i ne l ocat i on or [ Mt ext / Text/ Angl e] : ( Specify the

location of the dimension and other parameters such as multiline text, text style, inclination of

text)

Diameter: Measures the diameter of circles.

Tool Bar

Pull Down Dimension > Diameter

Keyboard DIMDIAMETER

Command

Sequence

Command: DI MDI AMETER

Sel ect ar c or ci r cl e: (pick object to measure)

Speci f y di mensi on l i ne l ocat i on or [ Mt ext/ Text/ Angl e] : ( Specify the

location of the dimension and other parameters such as multiline text, text style, inclination of

text)

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Angular: Measures the angle between two specified lines.

Tool Bar

Pull Down Dimension > Angular

Keyboard DIMANGULARCommand

Sequence

Command: DI MANGULAR

Sel ect arc, ci r cl e, l i ne, or : (pick first object which

contributes to the formation of the angle)

Sel ect second l i ne: (pick second object which contributes to the formation of the angle)

Speci f y di mensi on ar c l i ne l ocat i on or [ Mt ext / Text/ Angl e] : ( Specify

the location of the dimension and other parameters such as multiline text, text style, inclination of

text)

Quick Dimension: Dimensions several objects at one time.

Tool Bar

Pull Down Dimension > Quick Dimension

Keyboard QDIM

Command

Sequence

Command: QDI M

Associ at i ve di mensi on pr i ori t y = Endpoi nt

Sel ect geomet r y to di mensi on: (pick object to measure)

Sel ect geomet r y to di mensi on: (pick object to measure)

Sel ect geomet r y to di mensi on: (to end the selection)

Speci f y di mensi on l i ne posi t i on, or[ Cont i nuous/ St agger ed/ Basel i ne/ Or di nate/ Radi us/ Di ameter /

dat umPoi nt / Edi t / seTt i ngs] : ( Speci f y t he mode of

measur ement )

Baseline Dimension: Baseline line dimensions are a series of dimensions that all start from one point.

The first extension is the same for all dimensions. The second dimension includes the first dimension plus

an additional distance and so on.

Tool Bar

Pull Down Dimension > Baseline Dimension

Keyboard DIMBASELINE

Command

Sequence

Command: _di mbasel i ne

Speci f y a second ext ensi on l i ne ori gi n or [ Undo/ Sel ect ] :

( Pi ck t he next poi nt t o measur e)


(to end dimensioning)

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Continue Dimension: Continue Dimensions are a series of dimensions that are all attached. The Second

dimensions starts where the first dimension ends and so on.

Tool Bar

Pull Down Dimension > Continue DimensionKeyboard DIMCONTINUE

Command

Sequence






(to end dimensioning)

Quick Leader: Leaders are lines that aid designers in pointing to objects. Quick leader enable designers

to point and label on the model.

Tool Bar

Pull Down Dimension > Quick Leader

Keyboard QLEADER

Command

Sequence

Command: OFFSET

Speci f y f i r st l eader poi nt , or [ Set t i ngs] : ( Pi ck poi nt

t o comment on or SETTI NGS t o change t he paramet er s of t he l eader )

Speci f y next poi nt : ( Pi ck next t ur ni ng poi nt of t he l eader )Speci f y next poi nt : (to end drawing of the leader)

Speci f y t ext wi dt h : ( speci f y wi dt h of t he t ext )

Ent er f i r st l i ne of annot at i on text : ( Ent er t he text at

t he end of t he l eader)

Ent er next l i ne of annot at i on t ext: (to end comments)

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LAYERS

Layers are a way of managing, tidying and also controlling the visual layout of a drawing. A whole

section of a drawing can be turned on or off, or simply one aspect can be controlled. This is all done by

using layers within AutoCAD.

When a new AutoCad drawing is created, everything which is drawn is drawn on the one default layer,

named 0. When creating drawings, the layer 0 shouldn't really be used. New layers should be set up with

names corresponding to the content contained on them.

The separate lines and shapes representing each part of a composition would be arranged on its relevant

layers. Each layer could be assigned its own colour so that everything drawn on that layer appeared the

same colour. Layers have 4 states. These states control visibility, regeneration, editability and plottability

of the layers:

On/Off: On layers are visible. Off layers are invisible and are regenerated with the drawing. Off

layers are not plotted.

Thawed/Frozen: Thawed layers are visible. Frozen layers are invisible and are not regenerated

with the drawing. However, when you thaw a frozen later, the drawing regenerates.

Unlocked/Locked: Unlocked layers are visible and editable. Locked layers are visible but cannot

be edited.

Plottable/Not Plottable: Plottable layers are plotted. Not plotted layers are not plotted. This setting

affects only layers that are on or thawed because off and frozen are not plotted anyway.

Layers are controlled by the Quickfind Toolbar is found in the AutoCAD window by default.

Layer Properties Manager: The layer property manager is where all the layers are controlled. Thelayout below shows a typical use of layers. Brief description of the basic commands of the layer property

manager is also stated as follow.

Tool Bar

Pull Down Format > Layer

Keyboard Layer

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Generate

new layer

Delete

layer

Set current

layer

Layer

Groupings

Column Name Description

Shows the status of each layer

Used layerUnused layer

Status

Current layer

Name Shows the name of the layer. To change the layer, click once to display a

border and click again to type a new name.

On Shows the current on/off state of a layer.

Freeze Shows the current freeze/thaw state of a layer.

Lock Shows the current locked/unloced state of a layer.

Colour Shows the current colour of the layer.

Linetype Shows the current form (dotted, continuous etc) of the layer.

Lineweight Shows the current thickness of the layer.

Plot Style Shows the current plot style of the layer.

Plot Shows the current plottable/not plottable state of the layer

Description Provides a place to enter a description of a layer

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References

1. Finkelstein, Ellen. AutoCAD 2006 and AutoCAD LT 2006 bible, Hoboken, N.J. ; Chichester :

Wiley, 2005.

2. http://www.cadtutor.net/

3. http://www.we-r-here.com/cad/tutorials/
http://linc.nus.edu.sg/search/aFinkelstein%2C+Ellen./afinkelstein+ellen/-2,-1,0,B/browsehttp://www.cadtutor.net/http://www.we-r-here.com/cad/tutorials/level_2/2-8.htmhttp://www.we-r-here.com/cad/tutorials/level_2/2-8.htmhttp://www.cadtutor.net/http://linc.nus.edu.sg/search/aFinkelstein%2C+Ellen./afinkelstein+ellen/-2,-1,0,B/browse

autocad basic commands.pdf

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