2. Faculty of Electrical Engineering 1 Lecture : En. Syahrom Bin Zakaria EC202 COMPUTER AIDED DESIGN

3. 2 Tool bar Command prompt Button area Drawing window Object properties toolbar Standard toolbar Pull down menu

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5.  Always begin your drawing with the above dialog box. Your can set this dialog box via “Option dialog box”.  Select one of the system for your drawing, “metric” or “English”.  You begin your drawing with one this method:  start from scratch  use a template  use a wizard 4

6.  the keyboard,  icons and  pull-down menu. 5

7.  AutoCAD's drawing environment is based on the Cartesian coordinate system.  In a two-dimensional Cartesian coordinate system, two infinitely long axes are placed at right angles in a single plane. The horizontal axis is called the x-axis and the vertical axis is called the y-axis. 6

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10.  Absolute: x, y Represent the absolute real value of the drawing limits. 9

11.  Represents the relative position of x and y coordinates of the new point compared to the previous point. 10 Starting point 100 unit away from X, 0 unit away from Y 100 unit away from X 45 unit away from Y

12.  This system makes use of the distance and the direction angle of the new point away from the previous point. 11 Starting point 100 unit away from starting point at an angle of 45 o 100 unit away from starting point, at 0 o angle

13. 12 WCS in 2D WCS in 3D

14.  UCS allows you to shift the construction plane and simplify the location of three- dimensional points. 13 UCS in origin position

15. 14 UCS shifted from origin to inclined surface X for construction of a hole in 3D.

16.  Limits command help to define the drawing boundaries.  The current drawing area has a length of 12 units and a breadth of 9 units, by default for English system. For Metric System (SI), the drawing area has a length of 420 units and the breath of 297 units. 15

17.  The UNITS command governs the display and input formats for coordinates distances, and angles.  To execute the Units command, one can either select Units Control from the Settings pull-down menu or type UNITS at the Command prompt. 16

18.  This option allows us to specify all the necessary drawing aids that help in drawing design. To select this option, type command “DDRMODES” in command prompt option. 17

19.  Allow user to created objects more accurately and consistently maintain the result with far more precision. 18

20.  Specifies a point that is relative to the other points using orthogonal or polar displacement.  AutoTrack™ helps you draw objects at specific angles or in specific relationships to other objects. When you turn on AutoTrack, temporary alignment paths help you create objects at precise positions and angles. AutoTrack includes two tracking options: polar tracking and object snap tracking. You can toggle AutoTrack on and off with the Polar and Otrack buttons on the status bar. Object snap tracking works in conjunction with object snaps. You must set an object snap before you can track from an object's snap point. 19 Tracking

21.  In the following illustration, the Endpoint object snap is on. You start a line by clicking its start point (1), move the cursor over another line's endpoint (2) to acquire it, and then move the cursor along the horizontal alignment path to locate the endpoint you want for the line you are drawing (3). 20

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23.  Establishes a temporary reference point as a basis for specifying subsequent points.  Locates a point offset from a reference point within a command: FROM 22 Snap From

24.  Snap to Endpoint - Snaps to the closest endpoint of an object: ENDP  Example to draw an object (a circle) from endpoint A. 23 Endpoint

25.  A circle is accurately drawn from endpoint A. 24

26.  Snap to Midpoint. Snaps to the midpoint of an object: MID  Example to draw an object (a circle) from midpoint A. 25 Midpoint

27.  A circle is accurately drawn from midpoint A. 26

28.  Snaps to the intersection of two objects: INT  Example to draw an object (a circle) from intersection point A. 27 Snap to Intersection

29.  A circle is accurately drawn from intersection point A. 28

30.  Snaps to the apparent intersection of two objects: APPINT  Finds a point that represents the apparent intersection of two objects, such as two non- parallel lines that do not actually cross in 3D space. 29 Apparent Intersect

31.  Finds the center of a circle or an arc.  Draw a line from center A to center B 30 Center

32.  Snap from center A; then to center B 31

33.  Snaps to a quadrant point of an arc, circle, ellipse, or elliptical arc: QUA 32 Quadrant To draw a line from quadrant A to Quadrant B.

34.  Locates a point that is tangent to the selected circle or arc from either the last or the next point picked. 33 Tangent To a line from circle A tangent to circle B

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36.  Returns a point at the intersection of the object selected and an angle perpendicular to that object from either the last or the next point picked. 35 Perpendicular Draw a line perpendicular from midpoint A to BC

37.  Standard toolbar provides easy access to commands and modifiers of two types  The first type consists of commands that used to transfer, share, or import AutoCAD data into or with other Window’s applications  The second type of commands includes commands and modifiers that used frequently and might find handy to have available at the top of your drawing area 36

38. 37 line (a)Start Point, End Point Start point End point

39.  e.g. To draw a line starting from a point (30, 30), inclined at an angle of 45 o to the horizontal and has a length of 60 mm. 38

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41.  Figure below shows a rectangular ABCD. Draw the rectangular ABCD. Begin from point A, draw line AG and GH. From point D draw lines DE, EI, IF and FL. From J draw JK. 40

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43.  Draw the figure below and complete the given table. 42

44. Command : Line point AbsoluteRelativePolar From point A200,200 To point B C D E F G H I A 43

45. 44 Method of drawing circle in AutoCAD

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56.  Draw the template below: 55

57.  To draw line 56 Polyline

58. 57 Command : pline Specify start point : pick a point Specify next point or [Arc/Halfwidth/Length/Undo/width]: arc Specify endpoint of arc […………..]: pick a point and press enter

59.  Axis endpoint 58 Ellipse

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61. 60 To draw an elliptical arc of 270 0.

62. Specify axis endpoint of elliptical arc or [Center]: center Specify center of elliptical arc: 100,100 Specify endpoint of axis : 150,100 Specify distance to other axis or [Rotation]: 100,70 Specify start angle or [Parameter]: left click mouse once, Specify end angle or [Parameter/Included angle]: Included angle {then press enter} Specify included angle for arc :270 61

63. 62 Inscribed

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66. 65 The ERASE command lets you delete selected entities from the drawing. In order to access this command, you can either use Erase of the Modify menu or just type this command at the command prompt.

67.  The COPY command is used to duplicate one or more existing drawing entities to another location without erasing the original. While the Move command will cut out the drawing entities, and allows you to paste it to a new location. 66 Copy

68.  Move command will cut out the drawing entities, and allows you to paste it to a new location 67 Move The BREAK command deletes part of a Line, Trace, Circle, Arc, or Polyline, or splits the object into two objects of the same type

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70.  This command is used to change the orientation of existing entities by rotating them about a specified base point. 69 Rotate

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72.  The MIRROR command allows you to mirror selected entities in a drawing.  71 Mirror

73.  This command is a very important option that allows you to make multiple copies of selected objects in a rectangular or polar pattern. 72 Array

74. 73 Select type of array Select the object Define the distance for column and row

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76. 75 To array Object A 12 into 12 items

77. 76 Select object Select center point

78.  The Fillet command connects two lines, arcs, or circles with a smooth arc of specified radius. It adjusts the lengths of the original lines or arcs so they end exactly on the Fillet arc. 77 Fillet

79. Command: fillet Select first object or [Polyline/Radius/trim/mUltiple]:radius Specify fillet radius : 15 Select first object or [Polyline/Radius/trim/mUltiple]:(select the first object as shown) 78

80. 79 Select second object:

81. 80 Command: chamfer Select first object or [Polyline/Distance/Angle/trim/Method/ mUltiple]:distance Specify first chamfer distance : 15 Specify second chamfer distance : 15 [Polyline/Distance/Angle/trim/Method/ mUltiple]:pick first object

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83.  This command enable us to trim some objects in order to end preciously at a cutting edge (or edges) defined by one or more other objects. 82 Trim

84. Command : trim Select object : (select object entities as shown) {press enter after you have select the objects} 83

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