This course material is designed for Engineers and other interested personals who want to work specially mechanical drawings using AutoCad software. it is prepared just like a manual or guide line that can help the individuals learn autocad without any assistance. so enjoy it and if you have any question you can ask in my email: jerryhenok2016@gmail.com
3. COURSE CONTENT
1. Introduction to Basic CAD software
2. Basic Drawing & Editing Commands
3. Drawing Precision in CAD
4. Text Annotation and Dimensioning:
5. Introduction to 3D Drawings
6. Introduction to parametric design (Pro
Engineer
3
4. Content:
Basic principles of auto CAD
Introduction to AutoCAD
CAD window;
Setting up of a new drawing;
Working with an existing CAD
files;
Hardware and Software tips 4
1. Introduction to Basic CAD software
5. Introduction to AutoCAD
The role of computer in mechanical engineering
may be broadly classified in to two groups
1. Monitoring and controlling the mechanical
process. E.g. CNC, PLC, Robotics etc.
2. Support mechanical process applications.
Which deals essentially with the preparation
for actual manufacturing and post
manufacturing operations.
All the support functions that computers can
provide for the successful completion of
manufacturing operations.
The types of support can be CAD, CADD, CAE,
CAM, CAPP, CATD, CAP. 5
6. Introduction to AutoCAD
What is Auto CAD?
AutoCAD is a software package used for
Drafting and designing almost anything
you wish.
Design software developed by Auto-Desk.
First released in 1982 under the name
‘MicroCAD’.
Revolutionary drafting and design tool.
Translated into more than 18 different
languages.
6
7. CAD: Computer Aided Design
Use of computer methods to develop the geometric
model of the product(2D-3D)
It involves basically developing, analyzing and
modifying designs using computers.
CADD: Computer Aided Design and Drafting
Combine the CAD function with drafting
Used to generate the production drawing of the
part(detail drawings)
CAE: Computer Aided Engineering
The use of computer method to support basic error
checking, analysing, optimization, manufacturability,
etc of a product design. Like ANSIS-used to analyze
mechanical forces.
Terminology related to AutoCAD
7
8. CAM: Computer Aided Manufacturing
Refers to computer software used to develop the CNC-
part programs for machining and other process
applications.
CAPP: Computer Aided Process Planning
Use of computer to generate the process plans for
complete manufacture of products and parts.
CATD: Computer Aided Tool Design
Used for developing the tools for manufacture such as
jigs and fixtures, dies and moulds.
CAP: Computer Aided Planning
Involves the planning functions such as material
requirement planning, computer aided scheduling etc.
Cont’d
8
9. Application of CAD
CAD may be applied in the field of
both social and natural sciences as
far as they need to sketch or draw
some thing with the help of
computers.
Specifically it can be applied in:
Mechanical engineering
Civil engineering
Electrical engineering etc
9
12. Advantages of CAD
1. Faster rate of producing drawing
2. Greater accuracy of drawing
3. Neat and clear drawing
4. No reputation of design/drawing is just copy and
past with in a second
5. Special drafting techniques like zoom, rotate,
move, copy, mirror etc
6. Quickly and accurately dimensioning of various
components.
7. Superior design forms like finite element analysis
8. Integrating design department with other
department. Like CAM.
12
14. I. Starting Auto CAD
There are three methods of starting auto CAD
1. Opening Auto CAD from All programs
Start all programs Auto desk
AutoCAD2008 AutoCAD2008
2. Opening Auto CAD from desktop
Right-click on the shortcut icon on desk top the
drop-down menu appear then click on Open
On the screen /desktop/ double click on the
AutoCAD2008 shortcut icon.
3. Opening Auto CAD from program file
My comp C program file autocad2008
acad double click on it or Right-click and open
14
17. Basic components of CAD windows
1. Title bar
2. Menu bar
3. Drawing Area
4. Command pallet (area)
5. Status bar:
6. Toolbars
Standard toolbar
Object property toolbar
Drawing toolbar
Modifying toolbar
Style toolbar
Layer toolbar etc
17
18. The Auto CAD Interface cont’d
1. Title bar:
This is found at the top of the window
and it is by default with blue color.
It shows:
The auto cad version
The file location
The file name with its extension.
18
19. 2. Menu bar:
It is found at the top of the window
immediately below the title bar.
It contains File, Edit, View, Insert,
Format, Tools, Draw, Dimension, Modify,
Express, Window and Help.
These menus are sometimes called pull
down menus.
The Auto CAD Interface cont’d
19
20. 3. Drawing Area:
It is the area that we can draw and edit
our drawings.
It also contains :
the UCS (user coordinate system),
cross hair
There are two types of drawing areas:
Model window,
Layout window,
The Auto CAD Interface cont’d
20
21. 4. Command line:
Is used to insert necessary instruction to the
software.
It is used to Displays and prompts
messages.
The default position of the command line is
the bottom of the window immediately
above the status bar.
To display/hide the command line press
ctrl+9 on the keyboard
21
The Auto CAD Interface cont’d
22. 5. Status bar:
This part of auto cad window is found at the bottom of the
window.
It contains:
SNAP
GRID
ORTHO
POLAR
OSNAP
MODEL / PAPER
We can display or hide elements of status bar by
the status bar menu icon.
Also display x, y and z coordinate of the cursor.
A click on a button turns that function on, if it is
off, a click on a button when it is off turns the
function back on.
The Auto CAD Interface cont’d
22
23. 6. Tool bars:
It Contains many icons of a particular category
to access a command position without using
menu system.
There are above 30 toolbars Some of them are
for 2D window tasks and some are for only 3D
window tasks and the others are for both 2D
and 3D window tasks.
The toolbars that we frequently use are:
Standard toolbar,
Draw toolbar,
Modify toolbar,
Layers toolbar,
Properties toolbar,
Dimension toolbar,
Styles toolbar,
Inquiry toolbar,
Visual styles or Shade,
View port,
View,
Modeling toolbar,
Orbit,
Text, and etc
The Auto CAD Interface cont’d
23
24. A. Standard toolbar
Standard toolbar is docked at the top of the
AutoCAD window under the Menu bar.
It contains basic commands like open, save, print,
etc
24
cont’d
25. B. Object properties
You can use the controls in the Properties
toolbar to view, set, and modify the
properties.
The Properties toolbar provides convenient
access to the most important object
properties, Such as; Color, Line type, Line
weight, and Plot style,
25
cont’d
26. C. Layers
Layers are a way of managing, tidying and also controlling
the visual layout of a drawing.
Layers are used to group information in a drawing by
function and to enforce linetype, color, line weight and other
standards.
This makes working with very complicated drawings much
more easier and efficient.
Layers are effective way of ordering your drawings.
26
cont’d
27. 27
In Auto CAD, we make individual layers For
things like:
Part drawing
Dimensions
Hidden lines
Center lines
Section lines
Break lines
cont’d
28. Other terms used in ACAD
Dialog box: is a menu(command box)
which appears after selecting a command
like point style, insert, color etc.
In dialog box their may be one/both of the
following options
A. Tabs: a way/guide to bring a sub-dialog on screen.
B. Check boxes: guide to on off the indicated functions
C. Radio button: to indicate the feature description.
D. Slider: have pointer can be dragged to change size of
the feature controlled. 28
29. III. Setting of paper (Drawing area)
1. UNIT STYLE
Used to select any unit system (metric or inch)
and precision which can be displayed on a
coordinates or dimensions.
To promote the unit basically there are two
methods
a. METHOD-I: using command window
Type units and enter in a command
window
b. METHOD-II: using menu bar
Menu – Format – Units then select the
units and precisions
29
30. Setting of paper………..
2. DRAWING LIMIT
Is the invisible boundary to fit the drawing
It should be large enough to contain the
drawing and other related parts of it
To promote there are two methods
a. METHOD-I: using command window
Type Limits and enter in a command
window
b. METHOD-II: using menu bar
Menu – Format – drawing limit then specify
the size of paper (use 0,0 and 420,297 as default)
To activate the selected limit in command window type Z
enter and A enter 30
31. 3. Drafting setting
Is used to set Snap, Grid, Polar, Object
Snap Dynamic inputs etc
To promote there are two methods
a. METHOD-I: using command window
Type ds and enter in a command window
b. METHOD-II: using menu bar
Menu – tools – draft settings then specify
Snap and Grid, Polar, Object Snap
Dynamic inputs etc
Setting of paper………..
31
32. Saving files
Saving files: To save a file we have to consider;
file location
file name
file type like
.dwg: AutoCAD drawing
.dws: AutoCAD Drawing Standard
.dwt: AutoCAD Template Drawing template file
.dxf: AutoCAD Data Exchange Format
Remember: after you set the paper size units and other
necessary thing it is better to save the file as your
template this can save a lot of time 32
33. Executing toolbars
It is known as calling toolbars
If there is no tool bars except menu bar,
command window and title bar on CAD-window
there are two methods of calling tool bars:
1. Using commanding window follows steps:
Write CUI enter (customize user interface)
Cui dialog box appears on the first area:
Select ACAD Right click on it Select
Reset ACAD warning dialog box come
click yes then click apply then ok
Then go to Tool work space check Autocad
classical then standard tool bars will appear.
33
34. Cont’d
2. To add or call other necessary tool
bar other than the standard one
use the following steps:
Right click in any toolbar
Dropdown menu will come then
Select the toolbars you want to
see on ACAD graphic window.
34
38. I. Basic Geometrical objects and Tools
CONTENTS
1. Line
2. Polyline
3. Multi line
4. Polygons
5. Rectangle
6. Arc
7. Circle
8. Ellipse
38
39. 1. Drawing of lines
There are d/t methods of drawing a line
METHOD-I: using Grids and Snap command
Set grid and snap (10 and 5 as default)
Turn on grid and snap others off
Move the cursor until the following coordinates are
shown in the status bar
1. 60,140
2. 80,140
3. 80,120
4. 100,120
5. 100,100
6. 80,100
7. 80,50
8. 85,50
9. 85,40
10. 55,40
11. 55,50
12. 60,50
13. 60,100
14. 40,100
15. 40,120
16. 60,120
17. 60,140
1
39
40. METHOD-II: using Ortho command(direct entry
method)
Turn ‘on’ ORTHO and off others
Menu – Draw-Line
First point: pick on any point or specify
x, y
Second point: drag to right/left enter
the dimension and enter/right-click
Practice this:-
Drawing of lines….
40
41. METHOD-III: using coordinate entry methods
(CEM)
Basically there are Four CEM
A. Cartesion coordinate system(x,y,z)
Is used to explain a point by giving the x, y and z axis
coordinates
Eg. Draw an object using the following x,y & z
1. St.(20,10,0)
2. 30,10,0
3. 30,20,0
4. 40,20,0
5. 40,30,0
6. 10,30,0
7.10,20,0
8. 20,20,0
9. 20,10,0(or type
C and enter)
Drawing of lines…..
41
42. B. Absolute coordinate systems(x , y)
Is used to draw the object only by feeding
the x & y coordinates from the origin.
Eg. Draw an object using the following x & y
42
1. St.(20,10)
2. 30,10
3. 30,20
4. 40,20
5. 40,30
6. 10,30
7.10,20
8. 20,20
9. 20,10(or type C
and enter)
Drawing of lines…..
43. C. Relative coordinate system(@x , y)
Is a method used to draw a line relative
to the current position of a cursor OR the
point which drawn previously.
Eg. Draw an object using the following x &
y coordinates:- draw- line- then enter
below
1. 10,10
2. @40,0
3. @0,10
4.@-30,0
5.@0,10
6.@30,0
7.@0,10
8.@-30,0
9.@0,10
10.@30,0
11.@0,10
12.@-40,0
13.@0,-50 or
type C and
press enter
Drawing of lines…..
43
44. D. Polar coordinate system(D<θ)
A method used to draw an object if the
distance D and the angle θ b/n the
coordinates are given
Eg. Draw an object using the following
D&θcoordinates:- draw- line- then enter below
Drawing of lines…..
1. 50,50
2.@20<0
3.@20<60
4.@20<120
5.@-20<0
6.@20<240
7.@20<300 or type C and press enter
44
45. Multiline: Are composed of one or more
parallel line called elements
It is basically used to draw building
and factory layout drawings.
To promote multiline
Using menu bar: draw-multiline
2. Drawing of Multi line
45
46. Polyline: is a continuous line used to construct
continuous polygons like triangles, rectangle
etc.
It is a series of connected line and arc
segments created as one object.
Width of the object can also be controlled.
To promote Polyline
Using menu bar: draw-Polyline
Using command window: type pl or pline then
enter- specify points
3. Drawing of Polyline
46
47. The Polyline cont’d
The Polyline Command is found at:
Toolbar : Draw
Dashboard:
Steps to create Polyline
a. To draw a Polyline with straight segments
1. Take a Polyline command,
2. Specify the first point of the polyline,
3. Specify the endpoint of the first Polyline segment,
4. Continue specifying segment endpoints as needed,
5. Press ENTER to end, or enter c to close the
Polyline.
47
48. b. To draw a line and arc combination Polyline
1. Take a Polyline command,
2. Specify the start point of the polyline
segment,
3. Specify the endpoint of the Polyline segment,
Switch to Arc mode by entering a (Arc) on
the command line,
Return to Line mode by entering L (line),
4. Specify additional polyline segments as needed,
5. Press ENTER to end, or enter C to close the
Polyline.
Steps to create Polyline
48
49. c. To create a wide Polyline
1. Take a Polyline command,
2. Specify the start point of the line segment,
3. Enter w (Width,
4. Enter the starting width of the line segment,
5. Specify the ending width of the line segment using
one of the following methods:
To create a line segment of equal width, press
ENTER,
To create a tapering line segment, enter a
different width,
5. Specify the endpoint of the polyline segment,
6. Continue specifying segment endpoints as needed,
7. Press ENTER to end, or enter c to close the polyline,
Steps to create Polyline
49
50. Polygons: Is a plane figure with at least three
straight sides and angles, and typically five or
more.
The Polygon command is the simplest method
for creating equilateral triangles, squares,
pentagons, hexagons, and so on.
Use polygon to create closed polylines with
between 3 and 1,024 equal-length sides.
The Polygon Command is found at:
Toolbar: Draw
Dashboard:
Pull-down: Draw Polygon
Keyboard: POLYGON shortcut POL
4. Drawing of Regular Polygons
50
51. I. Inscribed in a Circle
Steps:
1. Take a Polygon command,
2. Enter the number of sides, for
example, 6,
3. Specifies the center to location
for the center of the polygon
4. Specify the Inscribed type I and
enter. This determines how the
distance that you enter in the
next prompt is measured
51
Drawing of Polygons……
There are three ways of constructing a polygon
52. II. Circumscribed about Circle
Steps:
1. Take a Polygon command,
2. Enter the number of sides,
for example, 6,
3. Specifies the center to
location for the center of the
polygon
4. Specify the Circumscribed.
type C and enter, This
determines how the distance
that you enter in the next
prompt is measured
Regular Polygons………..
52
53. III. Edge
Steps to draw a polygon by specifying
one edge:
1. Take a Polygon command,
2. On the command line, enter the
number of sides,
3. Select (Edge): type e and Enter
4. Specify the start point for one
polygon segment.
5. Specify the endpoint of the
polygon segment.
6. Click to define orientation for the
polygon.
Regular Polygons………..
53
54. 5. Drawing of Rectangle
The Use of Rectangle is to create closed polylines
in a rectangular shape.
The Rectangle Command is found at:
Toolbar: Draw
Dashboard:
Pull-down: Draw Rectangle
Keyboard: RECTANGLE shortcuts REC
This command is promoted: Specify first
corner point or [Chamfer/ Elevation/ Fillet/
Thickness/ Width]:
The Rectangle command
54
55. The Rectangle cont’d
Notice that; instead of picking a second point to
draw the rectangle ,you have option of entering
dimensions. You can specify the length, width,
area, and rotation parameters.
Steps:
1. Take a Rectangle command,
2. Specify the first corner of the rectangle,
3. Specify the other corner of the rectangle, or
4. Enter ‘D’ for dimension,
5. Give length value,
6. Give width value,
7. Click for orientation. 55
56. The Arc Command is found at:
Toolbar: Draw
Dashboard:
Pull-down menu: Draw Arc
Keyboard: Arc shortcut A
Steps: To draw an arc by specifying three
points
1. Take the arc command,
2. Specify the start point,
3. Specify a point on the arc,
4. Specify the endpoint.
6. Drawing of Arcs
56
57. There are 11- methods used to draw an arc
To call go to menu bar-Draw-Arc-the following
drop-down menu is appear then select the
method you want.
Drawing of Arcs…..
57
58. The circle Command is found at:
Toolbar: Draw
Dashboard:
Pull-down menu: Draw Circle
Keyboard: Circle shortcut C
Steps:
1. Take the circle command,
2. Specify the center point,
3. Specify the radius or diameter.
7. Drawing of circle
58
59. There are 6-d/t methods
used to draw a circles.
These are:
1. Center , Radius
2. Center , Diameter
3. 2 point method
4. 3 point method
5. Tan , Tan, Radius and
6. Tan, Tan, Tan
Drawing of circle….
59
60. Donuts are filled rings or solid-filled
circles that actually are closed Polyline
with width.
To create a donut, you specify its inside
and outside diameters and its center.
You can continue creating multiple
copies with the same diameter by
specifying different center points.
To create solid-filled circles, specify an
inside diameter of 0.
8. The Donut Command
60
61. The Donut cont’d
The Donut Command is found at:
Pull-down menu: Draw Donut
Keyboard: DONUT shortcut DO
Steps:
1. Take the command,
2. Specify the inside diameter,
3. Specify the outside diameter,
4. Specify the center of the donut,
5. Specify the center point for another
donut, or press ENTER to complete the
command. 61
62. There are 3- methods used to draw an arc
To call go to menu bar-Draw-Ellipse-the
following drop-down menu is appear then
select the method you want.
9. Drawing of Ellipse
62
63. You can hatch an enclosed area or hatch within a
specified boundary using HATCH.
By default, HATCH creates associative hatches that are
updated when the boundary is changed.
You create a hatch by selecting an object to hatch or by
defining a boundary and then specifying an internal
point.
A hatch boundary can be any combination of objects,
such as lines, arcs, circles, and Polyline, that forms an
enclosed area.
The Hatch and Gradient Command is found at:
Toolbar: Draw
Dashboard:
Pull-down menu: Draw Hatch/gradient
Keyboard: Hatch shortcut H 63
10. Hatch and Gradient
64. Hatch and Gradient Cont’d
To hatch areas
1. Take the Hatch or Gradient command,
2. In the Hatch and Gradient dialog box, click Add:
Pick points
3. In your drawing, specify a point inside each area
that you want hatched, and then press ENTER.
This point is known as the internal point.
4. In the Hatch and Gradient dialog box, Hatch tab,
in the swatch box, verify that the sample pattern
is the pattern you want to use. To change
patterns, select another pattern from the Pattern
list.
5. Click OK. 64
65. 11. Layer
What is a Layer?
A layer can be thought of as a large piece
of clear plastic, as infinitely large as the
drawing area in Autocad.
When drawing in Autocad, everything is
drawn on the default layer which is set
current. Only the objects you are drawing
are visible on the layer, the layer itself
can never be seen - it is invisible.
66. Layers
In Auto CAD, we make individual
layers…
For things like
Hidden lines
Center lines
Section lines
Break lines
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 - text for example.
67. Layers
This is all done by using layers within
Autocad.
Layers are controlled by the layer properties
manager button which is located on the
object properties toolbar:
Each new layer is created by you, the user.
Normally, it is acceptable to have a layer for
each different part of a drawing.
69. In Layer Property manger
Add a New Layer - Press the New button to
create a new layer.
Delete a Layer - Press the delete button to
delete the selected layer.
Set Current layer - Press the current button to
set the selected layer current. All objects drawn
will then be drawn on this current layer.
Show Details - Press the show details button
to see more detailed information about the
selected layer.
Each layer also has the following options against
it:
70. Layer property Manger
Name - Displays the layer name.
On - Controls if the layer is on or off. Select the light bulb to turn the layer
off on the drawing.
Freeze in all VP - Pressing this will freeze the layer in all viewports as well
as the current model view (see lesson 10 to learn about viewports)
Lock - This handy feature locks a layer preventing any content of the layer
from being modified.
Colour - Change this to whichever colour you like. All objects drawn on the
layer will display the chosen colour provided that the objects colour setting in
the object properties toolbar (shown above) is set to 'By Layer'.
Linetype - Set the default linetype for all objects drawn on the layer. i.e
continuous, dashed, dotted etc.
Lineweight - Set the thickness a line appears .Default is no thickness. This
option can be toggled on/off on the display by the LWT button above the
command console.
Plot - Select if the layer will be shown when the drawing is plotted (printed).
The current layer, layer colour, linetype and lineweight can all be controlled
outside of the layer properties manager via the object properties toolbar.
71. Exercise-1 ***
Additional
1. Draw polygon having 3, 5, 6, 7, 8 sides
inscribed and circumscribed about a
circles of diameter 40.
2. Draw a two different rectangle and practice
create Hatch and Gradient.
71
73. 3. Drawing Precision in CAD
CONTENTS
Advanced editing commands
Using Object Snap;
Making changes in a drawing;
Changing an object's length;
Blocks and Attributes.
73
74. Modifying Tools
Are the tools used to modify the
existing/current drawings to change their
shapes or some parts of it.
To call go to menu bar-modify-the following
drop-down menu is appear then select the
method you want.
Some of the basic modifying tools are: Erase,
Copy, Mirror, Offset, Array, Move, Rotate,
Scale, Trim.
Most of Modify tools can be accessed in one of
the following four ways;
1. By Keyboard,
2. By Dashboard,
3. By Modify Pull-down menu,
4. By Modify Tool bar,
74
75. 1. The Erase Command
The Erase Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Erase
Keyboard: ERASE; Shortcut: E
Steps:
1. Take Erase command,
2. Select Objects to erase,
3. Enter.
75
76. 2. The Copy Command
The Copy Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Copy
Keyboard: COPY; Shortcut: Co
Steps:
1. Take Copy command,
2. Select Objects to copy,
3. Specify the base point,
4. Specify the destination point, or points
5. Enter to end. 76
77. 3. The Mirror Command
The Mirror Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Mirror
Keyboard: Mirror; Shortcut: Mi
Steps:
1. Take Mirror command,
2. Select Objects to mirror,
3. Specify the first and the second point of the
mirroring line
4. Enter Y or N for erasing the original object
or not.
77
78. 4. The Offset Command
The Offset Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Offset
Keyboard: OFFSET; Shortcut: O
Steps:
1. Take Offset command,
2. Select Objects to offset,
3. Specify offset distance or the through point,
4. Specify the direction or the through point,
5. Enter to end.
78
79. Array command is used to Creates multiple
copies of objects in a pattern.
Use the Rectangular Array option to create an array of
rows and columns of copies of the selected object.
Use the Polar Array option to create an array by
copying the selected objects around a center point.
Menus
Toolbar: Modify
Menu: Modify Array...At the Command
prompt, enter array.
Command entry: array
79
5. The Array Command
80. I. To create a Rectangular array
1. Click Modify menu Array....At the Command prompt, enter array.
2. In the Array dialog box, select Rectangular Array.
3. Click Select Objects. The Array dialog box closes. You are prompted for
object selection.
4. Select the objects to be arrayed and press ENTER.
5. In the Rows and Columns boxes, enter the number of rows and columns in the
array.
6. Specify the horizontal and vertical spacing (offsets) between objects by using
one of the following methods:
In the Row Offset and Column Offset boxes, enter the distance between rows and
between columns. Adding a plus sign (+) or a minus sign (-) determines direction.
Click the Pick Both Offsets button to use the pointing device to specify the
diagonal corners of a cell in the array. The cell determines the vertical and
horizontal spacing of the rows and columns.
Click the Pick Row Offset or Pick Column Offset button to use the pointing device
to specify the horizontal and vertical spacing. 80
81. 7. The example box displays the result.
8. To change the rotation angle of the array, enter the new
angle next to Angle of Array.
9. The default angle 0 direction setting can also be changed in
UNITS.
10. Click OK to create the array.
81
To create a Rectangular array…..
82. 1. Click Modify menu Array....At the Command prompt, enter array.
2. In the Array dialog box, select Polar Array.
3. Next to Center Point, do one of the following:
Enter an X value and a Y value for the center point of the polar
array.
Click the Pick Center Point button. The Array dialog box closes
and you are prompted for object selection. Use the pointing device
to specify the center point of the polar array.
4. Click Select Objects. The Array dialog box closes and you are
prompted for object selection.
5. Select the objects to be arrayed.
6. In the Method box, select one of the following methods:
Total Number of Items & Angle to Fill
Total Number of Items & Angle Between Items
Angle to Fill & Angle Between Items 82
II. To create a Polar array
83. 7. Enter the number of items (including the original object), if available.
8. Use one of the following methods:
Enter the angle to fill and angle between items, if available. Angle to Fill
specifies the distance to fill around the circumference of the array. Angle
Between Items specifies the distance between each item.
Click the Pick Angle to Fill button and the Pick Angle Between Items
button. Use the pointing device to specify the angle to fill and the angle
between items.
The example box displays the result.
9. You can set any of the following options:
7. To rotate the objects as they are arrayed, select Rotate Items As Copied.
The example area displays the result.
8. To specify the X,Y base point, select More, clear the Set to Object's
Default option and enter values in the X and Y boxes, or click the Pick
Base Point button and use the pointing device to specify the point.
10. Click OK to create the array.
83
To create a Polar array …..
85. 6. The Move Command
The Move Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Move
Keyboard: Move; Shortcut: M
Steps:
1. Take Move command,
2. Select Objects to move,
3. Specify a base point for the move.
4. Specify the destination point,
The objects you selected can be moved to a new
location determined by the distance and direction
between the first and second (destination) points.
85
86. 7. The Rotate Command
The Rotate Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Rotate
Keyboard: ROTATE; Shortcut: Ro
Steps:
1. Take Rotate command,
2. Select Objects to rotate,
3. Specify the base point for the rotation,
4. Do one of the following:
86
87. The Rotate Cont’d
a. Enter the angle of rotation.
b. Drag the object around its base point
and specify a point location to which
you want to rotate the object.
c. Enter c to create a copy of the selected
objects.
d. Enter r to rotate the selected objects
from a specified reference angle to an
absolute angle
87
88. 8. The Scale Command
The Scale Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Scale
Keyboard: SCALE; Shortcut: Sc
Steps:
1. Take Scale command,
2. Select Objects to scale,
3. Specify the base point,
4. Do one of the following:
a. Enter the scale factor, or
b. Drag and click to specify a new scale, or
c. Enter r (Reference); then
Select the first and second reference points, or
enter a value for the reference length. 88
89. 9. The Stretch Command
The Stretch Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Stretch
Keyboard: STRETCH; Shortcut: S
Steps:
1. Take Stretch command,
2. Select Objects with cross window selection,
The crossing window must include at least
one vertex or endpoint.
3. Specify the base point for the stretch, and
then specify a second point, to determine
the distance and direction.
89
90. 10. The Trim Command
The Trim Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Trim
Keyboard: TRIM; Shortcut: Tr
Steps:
1. Take Trim command,
2. Select the objects to serve as cutting
edges, To select all displayed objects as
potential cutting edges, press ENTER without
selecting any objects.
3. Select the Objects to trim.
90
91. 11. The Extend Command
The Extend Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Extend
Keyboard: EXTEND; Shortcut: Ex
Steps:
1. Take Extend command,
2. Select the objects to serve as boundary
edges, To select all displayed objects as
potential boundary edges, press ENTER without
selecting any objects.
3. Select the Objects to extend.
91
92. 12. The Join Command
The Join Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Join
Keyboard: JOIN; Shortcut: J
Steps:
1. Take Join command,
2. Select the source object to which you want to
join objects.
3. Select one or more objects to join to the
source object. (Valid objects include arcs, elliptical
arcs, lines, Polyline, and spines)
4. Enter. 92
93. 13. The Chamfer Command
The Chamfer Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Chamfer
Keyboard: CHAMFER; Shortcut: Cha
The Chamfer command enables you to create a
chamfer between any two non-parallel lines.
Usually, the Chamfer command is used to set the
chamfer distances before drawing the chamfer.
93
94. The Chamfer Cont’d
Steps:
1. Take Chamfer command,
2. Select the first line,
3. Select the second line.
To set chamfer distances:
1.Take Chamfer command,
2.Enter d (Distances),
3.Enter the first chamfer distance,
4.Enter the second chamfer distance,
5.Select the lines for chamfering.
94
95. 14. The Explode Command
The Explode Command is found at:
Toolbar: Modify
Dashboard:
Pull down menu: Modify Explode
Keyboard: EXPLODE; Shortcut: Xp
Steps:
1. Take Explode command,
2. Select Objects to explode, and Enter.
If you need to modify one or more objects
within a block separately, you can disassemble,
or explode, the block reference into its
component objects.
95
96. Block and attributes
96
Blocks are drawings which can be
inserted into other drawings.
Blocks are contained in the data of the
drawing in which they have been
constructed.
Wblocks (written blocks) are saved as
drawings in their own right, but can be
inserted into other drawings if required.
To creat a block first draw the component
you need and follow the steps:
97. Block and attributes
97
To Make a Block of previously drawn object follow
the steps:
Go to Menu bar – draw – block – make then
block definition dialog box appears. Then do the
following:
A. Enter name of the block in the Name field.
B. Click the Select objects button. The dialog disappears.
On drawing Window select the object. The dialog
reappears. OR Click the Pick Point button. The dialog
disappears. Click a point on the drawing to determine
its insertion point. The dialog reappears.
C. If thought necessary enter a description in the
Description field of the dialog.
D. Click the OK button. The drawing is now saved as a
block in the drawing
98. Insert Block
98
To insert a Block which is previously created follow
the steps:
Go to Menu bar – insert – block then insert
dialog box appears. Then do the following:
A. Enter name of the block in the Name field.
B. Specify insertion point select on screen if you want
to show the point on screen OR specify X,Y & Z
coordinate of the insertion point. The dialog
reappears.
C. Show the point where you want to insert the block
D. Click the OK button. The block is now inserted.
100. 4. Text Annotation and
Dimensioning in Auto CAD
CONTENTS
Adding text to drawing;
Adding Dimensions
Setting preconditions for dimensioning
Dimension style
Primary units
Dimensioning different features
100
101. Adding text to drawing
101
Text Command
To create single-line text
1. Click Draw menu » Text » Single Line Text.
2. Specify the insertion point for the first
character.
3. Specify the height of the text.
4. Specify the text style and text font and color.
5. Specify a text rotation angle. You can enter
an angle value or use your pointing device.
6. Enter the text. At the end of each line, press
ENTER.
7. Click Ok to end the command.
103. 1. Inch System
2. Metric (ISO)
3. Military (diverse)
4. Associations (also diverse)
103
Standards of Measurement:
Measurement unit: click [U.S. military]
Full name: click [U.S. military]
Plural form: clicks means kilometer
Category type: length
Scale factor: 1000
›› SI unit: meter
The SI base unit for length is the meter.
1 meter is equal to 0.001 click [U.S. military].
1 click = 1000 meters
Measurement set by an international
associations like: AMEC: The International
Association for Measurement and
Evaluation of Communication (also known
as)
104. Dimensions are applied to objects in a variety of styles:
1. Chain
i. Aligned
ii. Unidirectional
2. Tabular
3. Coordinate/Baseline
4. Ordinate
Dimensions styles
104
106. 1. Overall:
Width
Depth
Height
2. The actual size of features
(rounds, fillets, holes, arcs, etc.)
3. And where features are located
such as centers, angles,
etc.
Dimensions are used to show an object’s:-
106
107. 107
There are several ways in which the dimensions tools
can be called.
1.From the Dimensions control panel in the
DASHBOARD
2.Click Dimension in the menu bar. Tools can be
selected from the drop-down menu which appears.
3.From the Dimension toolbar. The toolbar can be
called to screen with a right-click in any toolbar on
screen followed by a click on Dimension in the popup
menu which appears.
4.By entering an abbreviation for a dimension tool at
the command line.
Any one of these methods can be used when
dimensioning a drawing, but some operators may well
decide to use a combination of the four methods.
The Dimension tools
108. 108
The Dimensioning Toolbar
The dimensioning commands can be easily
accessed by:
Right Click on an existing toolbar and
activate the dimensioning toolbar;
Or, From the “pull down” menu
View
Toolbars
110. Radius dimensions measure the radii of arcs and circles with
optional centerlines or a center mark. If Text Placement is set
to Over the Dimension Line, with a leader, the dimension is
applied with a leader line.
Radius Dimensioning
111. Diameter dimensions measure the diameters of arcs and circles with optional
centerlines or a center mark. If Text Placement is set to Over the Dimension
Line, with a leader, the dimension is applied with a leader line.
Diameter Dimensioning
DIMCENTER command creates the center mark or the centerlines of
circles and arcs.
Center Marks
112. Arc Length allows you to create length dimensions (see Figure
7–23) for an arc.
Arc Length Dimensioning
113. ANGULAR DIMENSION command allows to draw angular
dimensions using three points (vertex, point, point), between two
nonparallel lines, on an arc (between the two endpoints of the arc,
with the center as the vertex), and on a circle (between two points on
the circle, with the center as the vertex).
Angular Dimensioning
114. Baseline dimensioning is used to draw dimensions to multiple points from
a single datum baseline.
The first extension line origin of the initial dimension (it can be a linear,
angular, or ordinate dimension) establishes the base from which the
baseline dimensions are drawn.
AutoCAD automatically draws a dimension line/arc beyond the initial (or
previous baseline) dimension line/arc.
Baseline Dimensioning
115. Continue dimensioning is used for drawing a string of dimensions,
each of whose second extension line origin coincides with the next
dimension’s first extension line origin.
Continue Dimensioning
116. The DIMSPACE command allows you to specify the space
between the dimension lines of parallel linear or concentric arc
dimensions.
Dimension Space
Dimension Break
The DIMBREAK commnad allows you to create a break in a
dimension extension line where it crosses another line.
117. Quick Dimensioning is used to draw a string of dimensions
between all of the end and center points of the selected object(s).
Quick Dimensioning
MLEADER Command is used to to connect annotation to objects or
other features in the drawing.
Options include Leader Type, Leader Landing, Content Type,
Maxpoints, First Angle, and Second Angle.
Multileader
118. Add Leader Command is used to add leader line and arrow combinations
to an existing multileader.
Mutlileader Style Command is used to create or modify multileader style.
With a multileader style, you can specify formatting for landing lines, leader
lines, arrowheads, and content.
Multileader
119. AutoCAD provides a special set of subcommands for the two
major methods of specifying tolerances: Lateral Tolerance and
Geometric Tolerance.
Lateral tolerance draws the traditional symbols and text for
Limit, Plus or Minus (unilateral and bilateral), Single Limit,
and Angular tolerance dimensioning.
Lateral tolerance is the range from the smallest to the greatest
that a dimension is allowed to deviate and still be acceptable.
Lateral tolerance and its related settings are set in the
Dimension Style Manager dialog box (Tolerances tab).
Tolerances
121. Geometric tolerance draws a Feature Control Frame for use in
describing standard tolerances according to the geometric
tolerance conventions.
Geometric tolerancing is applied to forms, profiles, orientations,
locations, and runouts. Forms include squares, polygons, planes,
cylinders, and cones.
123. Oblique Dimensioning
OBLIQUE command allows to slant the extension lines of a linear
dimension to a specified angle.
The dimension line will follow the extension lines, retaining its original
direction. This is useful for having the dimension stay clear of other
dimensions or objects in your drawing. It is also a conventional method of
dimensioning isometric drawings.
AutoCAD allows to edit dimensions with MODIFY
commands and grip editing modes. Also, AutoCAD provides
two additional MODIFY commands specifically designed to
work on dimension text objects:
Dimedit
Dimtedit
Editing Dimension Text
124. DIMEDIT
DIMEDIT command allows to replace the dimension text
with new text, rotate the existing text, move the text to a new
location, and if necessary, restore the text back to its home
position, which is the position defined by the current style.
In addition, you also change the angle of the extension lines
(normally perpendicular) relative to the direction of the
dimension line.
Available options include:
Home selection returns the dimension text to its default
position.
New selection change the original dimension text to the
new text.
Rotate selection change the angle of the dimension text.
Oblique selection adjusts the obliquing angle of the
extension lines for linear dimensions.
125. DIMTEDIT
DIMTEDIT command is used to change the location of
dimension text (with the Left/Right/Home options) along the
dimension line and its angle (with the Rotate option).
Available options include:
Left selection cause the text to be drawn toward the left
extension line.
Right selection cause the text to be drawn toward the right
extension line.
Home selection returns the dimension text to its default
position.
Angle selection changes the angle of the dimension text.
126. Dimension style Manager allows to create new styles, sets the current style,
modifies styles, sets overrides on the current style, and compares styles.
Each time a dimension is drawn it conforms to the settings of the Dimensioning
System Variables in effect at the time. The entire set of Dimensioning System
Variable settings can be saved in their respective states as a Dimension Style.
Dimension Styles
Dimension Style Manager
130. Modify Dimension Style dialog box – Text selection
Dimensioning Text with various
Text appearance selections
Dimensioning Text with various
Text placement (horizontal) selection
131. Modify Dimension Style dialog box – Fit selection
Dimensioning examples with various Fit options
Dimensioning example with various
Text placement options
132. Modify Dimension Style dialog box – Primary Units selection
Dimensioning example with various
dimensioning unit formats
Dimensioning example with
prefix, suffix, and alternate units
134. DIMOVERRIDE command change one of the features in a dimension
without having to change its dimension style or create a new dimension
style.
Overriding the Dimension Feature
DIMENSION UPDATE command permits to make selected existing
dimension(s) conform to the settings of the current dimension style.
Updating Dimensions
135. The DIMINSPECT dimension adds or removes
inspection information for a selected dimension.
Inspection dimensions specify how frequently
manufactured parts should be checked to ensure
that the dimension value and tolerances of the
parts are within the specified range.
Inspecting Dimensions
140. Isometric means equal measure
All planes are equally or proportionately
shortened and tilted
All the major axes (X, Y, Z) are 120 degrees
apart
140
CUBE
I. ISOMETRIC DRAWING IN
AUTOCAD
141. Cont…
• Making an Isometric Drawing
141
30o 30o
60o60o
Isometric Axis
142. I. Setting up isometric grid/snap
• The grid/snap style should be changed to
isometric snap
– Right click on grid button on status bar, choose
‘Settings…’
– Drafting setting window displaying Snap and
Grid tab is displayed
Isometric Drawing using Auto
CAD
144. II. Changing isoplane
• Changing the isoplane – left, top, right
– Cycle by pressing CTRL+E or F5 or
– Command: isoplane {enter}
Right Top Left
145. III. Drawing lines, circles and arc
• Isometric lines and non-isometric lines can be drawn
using line or polyline command
• Isometric circle can be drawn using ellipse command
– Draw ellipse > isocircle
• Isometric quarter circle and semi circle can be drawn
using ellipse arc command
– Draw ellipse arc > isocircle
146. Creating round corner
Before After
Draw ellipse
arc
Draw another
ellipse arc
Draw straight
line from
midpoint of
top arc to
midpoint of bottom arc
Trim Trim Trim
147. IV. Dimensioning
• Use aligned dimension for linear dimensioning
• Use quick leader for isocircle
Aligned dimension
Quick leader
148. To make dimension aligned with isometric axes, follow few steps as:
- Type DIMEDIT
- Type O for Oblique
- Select the dimension to be aligned, then Enter
- Specify the obliquing angle
For example, using the object above, for clockwise alignment such
as 90, type 30 for the angle, whereas for 100, type -30 for the angle
since anti-clockwise alignment.
149. Dimensioning for Isocircle
1. Select Quick leader icon
2. Select the circle, then extend the leader line to appropriate
direction, click, then make short extension in horizontal
direction, click, then type corresponding value (example:
R20) for the dimension.
150. Other useful tips
• Use COPY command with polar relative
coordinate system or OSNAP.
• Do not use OFFSET command.
• Set up LAYER before drawing.
• Use construction line as a guide
(recommended to use different colour)
152. What is Modeling
a process of constructing a virtual 3D graphics
object
Modeling tools: creating and constructing
complex 3D models fast and easy.
Rendering is a process of creating images
from graphics models.
152
153. A graphics model
geometrical descriptions (particles, vertices,
polygons) and associated attributes (colors,
shadings, transparencies, materials)
can be saved in a file using a standard (3D
model) file format.
153
155. 1. Wireframe Model
Represents edge of actual
object
Surfaces of object are not
defined
Transparency and no
volume
2D objects in 3D space
Use Line, Circle, Arc
155
156. 2. Surface Model
Edges and surfaces are defined
Object has volume but no mass
Each surface is constructed individually
Each surface is created / move to the
correct orientation w.r.t other surfaces
Easier to visualize than wireframe
Can be displayed in wireframe or hidden
view
Draw / Surfaces…
Command: _hide
156
157. 3. Solid Model
A complete computerized replica of the actual
object
Complete surfaces, edges, interior features of
the object
Object has volume and mass
Can be displayed in wireframe or hidden view
Constructing primitive shapes
Using Boolean operations to create composite solid
157
158. Creating solid models.
A solid model is defined by volumes.
Hierarchy of entities from low to high:
keypoints lines areas volumes.
You cannot delete an entity if a higher-
order entity is attached to it.
158
Volumes
Areas
Lines &
KeypointsKeypoints
Lines
Areas
Volumes
159. Simple 3D Half-Spaces
Sphere
Cylinder
Cone
Torus
Box
Plane
it splits space into two infinite half-spaces
you can use an infinite cylinder and two planes to make a capped
cylinder
You can also get a box from 6 planes…
159
161. 1. Top-Down Modeling
Approaches
Top-down modeling starts with a definition of
volumes (or areas), which are then combined
in some fashion to create the final shape.
The volumes or areas that you initially define are
called primitives.
Primitives are located and oriented with the help
of the working plane.
The combinations used to produce the final shape
are called Boolean operations.
161
add
162. Primitives
2-D primitives: include rectangles, circles,
triangles, and other polygons.
When you create a 2-D primitive, a modeling
tool usually defines an area, along with its
underlying lines and key points.
162
163. Primitives
3-D primitives: blocks, cylinders, prisms,
spheres, and cones.
When you create a 3-D primitive, a modeling
tool usually defines a volume, along with its
underlying areas, lines and key points.
163
164. 2. Bottom-up modeling
Approaches
2. Bottom-up modeling starts with keypoints,
from which you “build up” lines, areas, etc.
You may combine both methods.
164
165. Constructive Solid Geometry
(CSG) Techniques
Primitive Solids
Draw / Solids…
Box
Cone
Cylinder
Extrude
Revolve
Sphere
Torus
Wedge
Boolean Operations
Modify / Solid Editing
…
Union
Joins selected solids
Subtract
Subtract one set of solids
from another
Intersect
Create a solid of
intersection (common
volume) from the
selected solids
165
+
166. Common Operations
Drawing
Environments
Metric unit orientation
Set the drawing limit
Set isometric
viewpoint
Primitive Solids and
2D Object
Solid boxes
Cylinders
Rectangular
Object Modification
Fillet
Extrude
Subtract
Union
Move
Dimensioning
166
167. Boolean Operations
Boolean operations: combinations of
geometric entities: add, subtract, intersect,
divide, glue, and overlap, etc.
The “input” to Boolean operations: geometric
entities, simple primitives or complicated
volumes imported from a CAD system.
167
add
Input entities Boolean operation Output entity(ies)
168. Boolean CSG Operations
Union
Addition, A Ú B
Intersection
A Ù B
Difference
Subtraction, A – B, A Ù not B
Difference is not commutative
168
169. A more complicated example
Difference of:
Intersection of Sphere and Cube
Union of 3 Cylinders
169
- =
172. Step 0: Setup the environment
Set the environment at start
up
Metric setting
Viewing in 3D
View / 3D Views / SW
Isometric
Select common operations
from Toolbar
View / Toolbars …
Select Solid Editing, View
Point, Object Snap, Modify,
172
173. Step 1: Solid box
Create solid box
at 0,0,0
Define size of the
box: 50,50,15
x, y, z coordinate
173
174. Step 2: Solid from 2D object
174
•Create separate object (2D
rectangular with the size 44,
44
•Round one corner: Fillet
(radius of 22)
•Create a solid object using
Extrude feature
•Draw / Solid / Extrude
•Height: 5; Taper: 0)
176. Step 4: Move Objects
Move rounded
square object to
the base part
Use object snap
to help locate the
positions
Subtract small
box from the
bigger box
176
177. Step 5: Move objects
177
• Move a cylinder object to
an appropriate position
Move at the base
of the cylinder to
22,22,10
• Combine (Union) 2
objects
178. Step 6: Round Corners
178
• Round the edges
using Fillet
(radius of 2)