CAEG IT-B.pptx

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1. 1 20ME272 COMPUTER AIDED ENGINEERING GRAPHICS Semester - II B.Tech . I nformation T echnology Academic Year : 2020-21 REGULATIONS 2020 Sri Ramakrishna Engineering College Vattamalaipalayam , Coimbatore – 22   Department of Mechanical Engineering

2. 20ME272 COMPUTER AIDED ENGINEERING GRAPHICS 2 P.Saravanakumar Assistant Professor(OG) Department of Mechanical Engineering Sri Ramakrishna Engineering College Coimbatore-641022

3. 3 20ME272 COMPUTER AIDED ENGINEERING GRAPHICS On successful completion of the course, the student will be able to Course Objectives CO1 Create geometric models using the basic commands and features of the drafting software. CO2 Construct simple geometric entities and their projections as per the BIS conventions. CO3 Convert the pictorial projections of geometric entities into orthographic projections. CO4 Draw the isometric view of simple geometric models. CO5 Manipulate the geometric entities created using drafting software

4. SYLLABUS 4

5. LIST OF EXPERIMENTS 1. Creation of drawing sheet layouts and title block. 2. Model simple two-dimensional graphical entities using absolute and relative co-ordinate methods. 3. Projection of points. 4. Projection of straight lines. 5. Projection of simple solids. 6. Construction of orthographic views of simple solids. 7. Modeling of isometric view of simple solids. 11/14/2021 5

6. Effectiveness of Graphics Language 11/14/2021 6

7. Effectiveness of Graphics Language 11/14/2021 7

8. Effectiveness of Graphics Language 11/14/2021 8

9. Effectiveness of Graphics Language 11/14/2021 9

10. Freehand drawing The lines are sketched without using instruments other than pencils and erasers. 11/14/2021 10

11. Freehand drawing The lines are sketched without using instruments other than pencils and erasers. 11/14/2021 11

12. Drawing by use of Instruments Instruments are used to draw straight lines, circles, and curves concisely and accurately. Thus, the drawings are usually made to scale. 11/14/2021 12

13. Drawing by use of Instruments 11/14/2021 13

14. Drawing by use of Computer The drawing are usually made by commercial software as AutoCAD, Solid works etc. 11/14/2021 14

15. Drawing by use of Computer 11/14/2021 15

16. Engineering Drawing 11/14/2021 16

17. Elements of Engineering Drawing 11/14/2021 17

18. Basic Knowledge for Drafting 11/14/2021 18

19. DEFINITION Standards are set of rules that govern how Technical drawings are represented. Drawing standards are used so that drawings convey the same meaning to everyone who reads them. 11/14/2021 19

20. Standard Code 11/14/2021 20

21. Drawing Sheet 11/14/2021 21

22. Drawing Scales Definition: Scale is define as ratio of linear dimensions of an element of an object represented in the original drawing to the linear dimension of the same element of the object by itself 11/14/2021 22

23. Basic Line Types 11/14/2021 23

24. Meaning of Lines 11/14/2021 24

25. 11/14/2021 25

26. DRAWING INSTRUMENTS USED IN ENGINEERING GRAPHICS 11/14/2021 26

27. DRAWING INSTRUMENTS 1.Drawing Board 2.Drawing Sheets 3.Standard Set-scales 4.Mini-Drafter 5.Instrument Box 6.Set-Squares ( 45,30 & 60 deg ) 7.Protractor-cum-Procircle 8.Drawing Pencils ( HB,H and 2H ) 9.Sharpener and Emery Paper 10.Adhesive Tape ( Cello-Tape )/ Clips 11.Pencil Eraser 12.French Curves 11/14/2021 27

28. DRAWING BOARD 11/14/2021 28

29. DRAWING BOARD TYPES 11/14/2021 29

30. DRAWING SHEETS 11/14/2021 30

31. Drawing sheet sizes 11/14/2021 31

32. DRAFTER 11/14/2021 32

33. DRAFTER 11/14/2021 33

34. Drawing Instruments Typical Drawing Equipment Objectives in Drawing Accuracy Speed Legibility Neatness 34

35. Drawing Instrument 11/14/2021 35

36. Compasses 11/14/2021 36

37. Compasses 11/14/2021 37

38. Compasses 11/14/2021 38

39. DRAWING INSTRUMENTS 11/14/2021 39

40. PENCILS 11/14/2021 40

41. Drawing Pencils Wooden pencils – are graded and designated by numbers and letters Mechanical clutch pencils – Not allowed • 7B, 6B, 5B, 4B, 3B, 2B, B - in decreasing order of softness and blackness • HB to F – Medium grade • H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H – increasing order of hardness. Drawings are done using 2H pencils and finished with H and HB pencils – to be practiced in this course. 41

42. Grades and designation of wooden pencils 42

43. Line types 43

44. Line types…. CONTD 44

45. DRAWING TOOLS 11/14/2021 45

46. DRAWING TOOLS 11/14/2021 46

47. DRAWING TOOLS 11/14/2021 47

48. DRAWING TOOLS 11/14/2021 48

49. DRAWING TOOLS 11/14/2021 49

50. DRAWING TOOLS 11/14/2021 50

51. French curve 11/14/2021 51

52. BIS conventions and specifications 11/14/2021 52

53. Experiment :01 Creation of drawing sheet layouts and title block 11/14/2021 53

54. Layout of A2 size Drawing Sheet 11/14/2021 54

55. Title Block 11/14/2021 55

56. Lettering Technique Lettering Techniques Most engineering lettering is single-stroke Gothic font. Lettering is drawn freehand and are drawn within light horizontal guidelines. Typically lettering is 1/8” high. All lettering uses upper case letters . Lower case letters are rarely used in technical drawings. There are three aspects of good lettering: proportions and forms of the letters, composition and spacing , and practice . There are six fundamental drawing strokes and their directions in basic lettering. Horizontal strokes are drawn from left to right, vertical strokes are drawn from top to bottom, and curved strokes are drawn downward. . 56

57. Lettering Technique . 57

58. Lettering 11/14/2021 58

59. Lettering 11/14/2021 59

60. 11/14/2021 60

61. Dimensioning Elements of Dimensioning Dimension line: Thin continuous line used to indicate the measurement. Extension line: Thin continuous line extending beyond the outline of the object. Arrow-head : Used to terminate the dimension line. Length : width ratio is 3:1. Space filled up. Note: Gives information regarding specific operation relating to a feature. Leader: Thin continuous line connecting a note or a dimension figure with the feature to which it is applied. Terminated by arrow-head or dot. Symbol: The representation of any object by some mark on the drawing. It saves time and labour. 11/14/2021 61

62. Dimensioning 11/14/2021 62

63. Methods of Dimensioning Aligned Method 11/14/2021 63

64. Methods of Dimensioning Aligned Method-Angular dimensions 11/14/2021 64

65. Arrangement of Dimensions Chain Dimensioning: Dimensions are arranged in a straight line. Parallel Dimensioning: All the dimensions are shown from a common base line. The smaller dimension is placed nearer the view. Combined Dimensioning: Chain and parallel dimensioning used simultaneously 11/14/2021 65

66. Arrangement of Dimensions Chain Dimensioning 11/14/2021 66

67. Arrangement of Dimensions Parallel Dimensioning 11/14/2021 67

68. Arrangement of Dimensions Combined Dimensioning 11/14/2021 68

69. Symbols for Shape Indication 11/14/2021 69

70. Symbols for Shape Indication 11/14/2021 70

71. Rules for Dimensioning 11/14/2021 71

72. Rules for Dimensioning 11/14/2021 72

73. Rules for Dimensioning 11/14/2021 73

74. Rules for Dimensioning 11/14/2021 74

75. Rules for Dimensioning 11/14/2021 75

76. AUTOCAD Example for computer aided drawing is AutoCAD • 2D and 3D computer aided drafting software application • Used for making blueprint 11/14/2021 76

77. AutoCAD Drawing 11/14/2021 77

78. AutoCAD Drawing 11/14/2021 78 In free hand or hand – held drawing error may occured • Dimensions are not in accurate points • In computer aided drafting (AutoCAD) there wont be any mistakes • Time taken is less

79. APPLICATIONS Civil Engineering • For construction of bridges, buildings and for making maps Mechanical Engineering • For designing machines, bike parts, car parts, etc ,... Electronics and Communication Engineering • For understanding circuit connections and component diagrams 11/14/2021 79

80. Drawing sheet sizes 11/14/2021 80

81. Layout of A2 size Drawing Sheet 11/14/2021 81

82. Title Block 11/14/2021 82

83. Experiment:02 Model simple two-dimensional graphical entities using absolute co-ordinate methods and relative co-ordinate methods . 11/14/2021 83

84. Example 11/14/2021 84

85. Absolute Coordinate System 11/14/2021 85

86. Relative Coordinate System 11/14/2021 86

87. Exercise 11/14/2021 87 Draw following figures using line commands

88. Exercise 11/14/2021 88

89. Coordinate System 11/14/2021 89 Absolute Coordinate System Relative Coordinate System

90. Experiment:03 Projection of points 11/14/2021 90

91. Projection of Point 11/14/2021 91

92. Projection of Point in different quadrants 11/14/2021 92

93. 11/14/2021 93

94. First angle vs Third angle 11/14/2021 94

95. ORTHOGRAPHIC PROJECTIONS OF POINTS 11/14/2021 95

96. NOTATIONS 11/14/2021 96

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98. 11/14/2021 98

99. PROJECTIONS OF A POINT IN FIRST QUADRANT . 11/14/2021 99

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103. 11/14/2021 103

104. Practice 11/14/2021 104

105. solution 11/14/2021 105

106. Experiment:04 Projection of straight lines 11/14/2021 106

107. Projection of straight lines Straight Lines A straight line is the shortest distance between two given points. Thus, the two ends of a straight line are points. Projection of a Straight line can therefore be drawn by joining the respective projection of its end points. 11/14/2021 107

108. Positions of a line with Respect to HP and VP 11/14/2021 108

109. 1.Parallel to Both the Planes HP and VP A line CD 30 mm long is parallel to both the planes. The line is 40 mm above HP and 25 mm in front of VP. Draw its projections. 11/14/2021 109

110. Parallel to Both HP and VP A line CD 30 mm long is parallel to both the planes . The line is 40 mm above HP and 25 mm in front of VP. Draw its projections. 11/14/2021 110

111. Line contained in one plane and Parallel to the other A line RS 60 mm long lies in HP and 45 mm in front of VP. Draw its projections. 11/14/2021 111

112. Line contained in one plane and Parallel to the other A line RS 60 mm long lies in HP and 45 mm in front of VP. Draw its projections. 11/14/2021 112

113. Line contained in one plane and Parallel to the other A line PQ 55 mm long is lying in VP and 45 mm above HP. Draw its projections. 11/14/2021 113

114. Line contained in one plane and Parallel to the other A line PQ 55 mm long is lying in VP and 45 mm above HP. Draw its projections. 11/14/2021 114

115. Line contained in Both HP and VP A line AB 55 mm long is lying on both HP and VP . Draw its projections. 11/14/2021 115

116. Line Perpendicular to one plane and Parallel to the other Line perpendicular to HP & parallel to VP A line AB 25 mm long is parallel to VP and perpendicular to HP. Point A is 35 mm above HP and 20 mm in front of VP. Point B is 10 mm above HP. Draw the projections of the line AB. 11/14/2021 116

117. Line Perpendicular to one plane and Parallel to the other Line perpendicular to HP & parallel to VP A line AB 25 mm long is parallel to VP and perpendicular to HP. Point A is 35 mm above HP and 20 mm in front of VP. Point B is 10 mm above HP. Draw the projections of the line AB. 11/14/2021 117

118. Line perpendicular to VP and Parallel to HP A line AB 25 mm long is perpendicular to VP and parallel to HP. Its end A is 10 mm in front of VP and the line is 20 mm above HP. Draw the projections of the line. 11/14/2021 118

119. Line perpendicular to VP and Parallel to HP 11/14/2021 119

120. Line Parallel to one plane & Inclined to other Line Parallel to VP & Inclined to HP A line PQ 40 mm long is parallel to VP and inclined at an angle of 30 to HP. The lower end P is 15 mm above HP and 20 mm in front of VP. Draw the projections of the line. 11/14/2021 120

121. Line Parallel to one plane & Inclined to other 11/14/2021 121

122. Line Parallel to HP & Inclined to VP Draw the projections of a line EF 40 mm long parallel to HP and inclined at 35 to VP. E is 20 mm above HP and 15 mm in front of VP. 11/14/2021 122

123. Line Parallel to HP & Inclined to VP 11/14/2021 123

124. Line contained by one plane and inclined to the other Line contained in VP & Inclined to HP A line AB 50 mm long is in VP and inclined at 35* to HP. End A is 10 mm above HP. Draw the projections. 11/14/2021 124

125. Line contained by one plane and inclined to the other 11/14/2021 125

126. Line contained by one plane and inclined to the other 11/14/2021 126 Line contained in HP & Inclined to VP A line RS measuring 52 mm is in HP and inclined at an angle of 45* to VP. The end R is 10 mm in front of VP. Draw the projections.

127. Line contained by one plane and inclined to the other 11/14/2021 127

128. Projections of Solids Any machine part or element or component is formed of a single solid or combination of solids of different shapes, known as Prisms, cylinders, Pyramids, Cones and Spheres. Solid : A Solid is defined as an object having three dimensions, viz., length, breadth and height or thickness, measured along the three mutually perpendicular axes. It is bounded by plane faces or curved surfaces or combination of both. 11/14/2021 128

129. Projections of Solids Classification of Solids: 1.Polyhedra 1.1 Regular Polyhedra i.Cube ii.Tetrahedron iii.Octahedron iv.Dodecahedron v.Icosahedron 1.2.Prisms 1.3.Pyramids 2.Solids of Revolution 2.1.Right Circular cylinder 2.2. Right Circular Cone 2.3.Sphere 3. Frustums & Truncated Solids 11/14/2021 129

130. Projections of Solids 11/14/2021 130

131. Projections of Solids 11/14/2021 131

132. Projections of Solids 11/14/2021 132

133. Projections of Solids 11/14/2021 133

134. Projections of Solids 11/14/2021 134

135. Projections of Solids 11/14/2021 135

136. Projections of Solids. Projections of Solids. Prism, Pyramid , Cylinder & Cone Perpendicular to HP 11/14/2021 136

137. Projections of Prism, Pyramid,Cylinder & Cone Axis Perpendicular to HP Problem:01 Draw the top and front views of a cube of 40 mm side resting with one of its square faces on HP such that one of its vertical faces is parallel to and 20 mm in front of VP. 11/14/2021 137

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140. Problem:02 Draw the projection of a square prism of side of base 30 mm and height 50 mm resting with its base on HP such that one of its rectangular faces is perpendicular to VP. The nearest edge parallel to VP is 5 mm in front of it. 11/14/2021 140

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143. Problem:03 A triangular prism side of base 35 mm and height 50 mm rests with its base on HP such that one of its rectangular faces is perpendicular to VP. Draw its projections. The nearest edge parallel to VP is 10 mm in front of it. 11/14/2021 143

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146. Problem:04 A triangular prism side of base 35 mm and axis 50 mm long rests with its base on HP such that one of its rectangular faces nearer to VP is parallel to and 8mm in front of it. Draw its projections. 11/14/2021 146

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148. Problem:05 Draw the projections of a regular pentagonal prism side of base 30 mm and axis 55 mm resting with its base on HP such that one of its rectangular faces is perpendicular to VP 11/14/2021 148

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150. Problem:06 Draw the projections of a hexagonal prism of side of base 25 mm and height 50 mm resting with its base on HP such that one of its rectangular faces is perpendicular to VP 11/14/2021 150

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152. Problem:07 A triangular prism of side of base 30 mm and height 45 mm rests with its base on HP such that one of its rectangular faces is parallel to and 40 mm farther away from VP. Draw its projections. 11/14/2021 152

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154. Problem:08 Draw the projections of a pentagonal prism side of base 30 mm and axis 60 mm long resting with its base on HP such that one of its rectangular faces is parallel to and 10 mm in front of VP 11/14/2021 154

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156. Axis Perpendicular to VP A hexagonal prism, side of base 25 mm and axis 60 mm long, lies with one of its rectangular faces on the HP such that the axis is perpendicular to the VP. Draw its projections. 11/14/2021 156

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158. Axis Perpendicular to VP A hexagonal pyramid of base side 25 mm and height 65 mm is kept such that the base is parallel to and 15 mm in front of VP with the edge perpendicular to HP. Draw the projections. 11/14/2021 158

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160. Inclined to HP and Parallel to VP A pentagonal prism side of base 25 mm and axis 50 mm long rests with one of its edges on HP such that the base containing that edge makes on angle 30* to HP and its axis is parallel to VP. Draw its Projections. 11/14/2021 160

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162. Sample Diagram 11/14/2021 162

163. Practice 11/14/2021 163

164. 11/14/2021 164

165. Practice 11/14/2021 165

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167. Practice 11/14/2021 167

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169. Practice 11/14/2021 169

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171. Isometric Projection Isometric projection is a method for visually representing three-dimensional objects in two dimensions in technical and engineering drawings. It is an axonometric projection in which the three coordinate axes appear equally foreshortened and the angles between any two of them are 120 degrees. 11/14/2021 171

172. Isometric Terminology The three coordinate axes are called isometric axes • Any line parallel to isometric axes is called isometric line • A  non-isometric line is a line not parallel   to   any   one   of   the three isometric axis • In isometric projection of cube, the faces of the cube and any plane parallel to them is called isometric planes 11/14/2021 172

173. Isometric Scale True lengths of the edges of the object are equally foreshortened • Correct isometric projection can be drawn using an isometric scale (always smaller than ordinary scale) 11/14/2021 173

174. Isometric Drawing 11/14/2021 174

175. Steps for construction of Isometric 11/14/2021 175

176. Steps for construction of Isometric 11/14/2021 176

177. Steps for construction of Isometric 11/14/2021 177

178. Steps for construction of Isometric 11/14/2021 178

179. Steps for construction of Isometric 11/14/2021 179

180. Objects with Circular Geometry 11/14/2021 180

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182. Cylinder 11/14/2021 182

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196. Thank you 11/14/2021 196