1. ENGINEERING DRAWING VISUALIZATION

2. Axonometric & Oblique Projection

3. Axonometric Projection A B C D Parallel & normal to picture plane Line of sight A B C D

4. Axonometric Projection Type of axonometric drawing a b c 2. Dimetric Two angles are equal. b a c 3. Trimetric None of angles are equal. a bc 1. IsometricAll angles are equal. A B C D A B C D Axonometric axis

5. A B C D Line of sight Parallel & oblique to picture plane Oblique Projection A D C B

6. A D C B B C D A Oblique drawing angle 30 o 45 o 60 o Type of Oblique drawing 45 o 1) Cavalier 2) Cabinet Full scale Half scale

7. Isometric Projection & Isometric drawing

8. Rotate 45  about vertical axis Tilt forward (35 o 16 ’ ) Isometric Projection All edges foreshorten about 0.8 time.

9. Isometric Drawing Isometric drawing is a drawing drawn on an isometric axes using full scale. Isometric projection (True projection) Isometric drawing (Full scale) Forshorten Full scale

10. Positions of Isometric Axes Isometric axes can be arbitrarily positioned to create different views of a single object. Regular isometric Reverse axis isometric Long axis isometric View point is looking down on the top of the object. View point is looking up on the bottom of the object. View point is looking from the right (or left) of the object.

11. Distance in Isometric Drawing Isometric line is the line that run parallel to any of the isometric axes. Isometric axes True-length distances are shown along isometric lines. Nonisometric lines

12. Isometric Sketching

13. STEPS 1. Positioning object. 2. Select isometric axis. 3. Sketch enclosing box. 4. Add details. 5. Darken visible lines. Sketch from an actual object

14. 1. Positioning object. 2. Select isometric axis. 3. Sketch enclosing box. 4. Add details. Note In isometric sketch/drawing), hidden lines are omitted unless they are absolutely necessary to completely describe the object. Sketch from an actual object STEPS 5. Darken visible lines.

15. 1. Interprete the meaning of lines/areas in multiview drawing. 2. Locate the lines or surfaces relative to isometric axis. Sketch from multiview drawing

16. Front View Top View Side View Example 1 : Object has only normal surfaces Bottom View Bottom Front Side Front Top Regular Reverse W D H H D W

17. Example 2 : Object has inclined surfaces W H  D y x Front View y x Nonisometric line

18. A A x y x x B B A B C C C x y Example 3 : Object has inclined surfaces

19. A A B B C D E D E F F x y Front View Regular C Example 4 Reverse

20. Circle & Arc in Isometric In isometric drawing, a circle appears as an ellipse. 2. Construct an isometric square. 3. Sketch arcs that connect the tangent points. Sketching Steps 1. Locate the centre of an ellipse.

21. Circle & Arc in Isometric 3. Construct a perpendicular bisector from each tangent point. 4. Locate the four centres. 5. Draw the arcs with these centres and tangent to isometric square. Sketching Steps Four-centre method is usually used when drawn an isometric ellipse with drawing instrument. 2. Construct an isometric square. 1. Locate the centre of an ellipse.

22. Example 5

23. Irregular Curve in Isometric 1. Construct points along the curve in multiview drawing. 2. Locate these points in the isometric view. 3. Sketch the connecting lines. Steps

24. Oblique Sketching

25. Object Orientation Guidelines Place complex features (arc, hole, irregular shape surface parallel to frontal plane.

26. Object Orientation Guidelines The longest dimension of an object should be parallel to the frontal plane. GOOD WORSE GOOD WORSE

27. Object Orientation Guidelines Which orientation is better ?

28. D 45  ESTIMATE DEPTH ESTIMATE LINES Sketch from actual object

29. Sketch from multiview drawing

31. AB C D E

32. A B C D E

33. A B D E C

34. A B D E C

35. Oblique and Isometric Drawings GSMST

36. Types Obliques – Cavalier – Cabinet Axonometrics – Isometrics – Others Perspectives

37. Types Obliques – Cavalier – Cabinet Axonometrics – Isometrics – Others Perspectives

38. Types Obliques – Cavalier – Cabinet Axonometrics – Isometrics – Others Perspectives

39. Cavalier Oblique Front view true size Receding Axis Angle (Normally 30°, 45° or 60°) is Variable Depth dimension (receding axis) true size

40. Cabinet Oblique Front view true size Receding Axis Angle (Normally 30°, 45° or 60°) is Variable Depth dimension (receding axis) half size

41. Side by Side Comparison Cavalier ObliqueCabinet Oblique

42. Which is the cube ?

43. Were you right?

44. Angles in Oblique Angles in front view are drawn true size Other angles must be located using coordinates Appearance of angles may be distorted

45. Circles in Oblique Drawn true size in front view Drawn as ellipses on receding planes Layout using a Rhombus

46. Cylinders in Oblique Front and Back surfaces are circular “Sides” are drawn as lines tangent to the front and back

47. Types of Axonometrics

48. Orientation of Pictorial Objects

49. Isometrics Axes equally separated (120°) H, W, and D measurements are true size along iso. axes Angles must be located by coordinates Circles appear as ellipses on all surfaces

50. Isometric Circles & Angles

51. Isometric Ellipses

52. The Isometric Ellipse Template

53. Using the Ellipse Template

54. Drawing Rounded Corners

55. Construction of Cylinders Lightly block in the cylinder

56. Construction of Cylinders Lightly block in the cylinder Sketch the upper and lower ellipses

57. Construction of Cylinders Lightly block in the cylinder Sketch the upper and lower ellipses Connect the ellipses with Tangent lines

58. Construction of Cylinders Lightly block in the cylinder Sketch the upper and lower ellipses Connect the ellipses with Tangent lines Darken the lines

59. Isometric Drawing Exercise You will use two different lines to sketch objects:  Construction lines are light lines sketched in as you initially draw the object.  Drawing lines are dark lines which may be used for the initial drawing or which may be created by neatly darkening a construction line.

60. Isometric Drawing Exercise To draw an isometric object using the box method, perform the following steps: Step 1: Draw a box around the object you wish to draw.

61. Isometric Drawing Exercise Step 2: Draw a box on your paper, in the same proportions as the box you drew on the object, 1½ to 2 times larger than the original box. Original box Proportional box

62. Isometric Drawing Exercise Step 3: Look at the front side of the object. Which surface touches the outside of the box? Step 4: Draw the surface on your box using drawing lines.

63. Isometric Drawing Exercise Step 5: Look at the top of the object. Which surface touches the outside of the box? Step 6: Draw the surface on your box using drawing lines.

64. Isometric Drawing Exercise Step 7: Look at the right hand side of the object. Which surface touches the outside of the box? Step 8: Draw the surface on your box using drawing lines.

65. Isometric Drawing Exercise Step 9: Complete the box by drawing in the “third lines”. You may wish to draw construction lines then neatly cover the construction lines with drawing lines.