Orthographic projection new (1)

Principle of orthographic projection
First and third angle projection

1. Presented by Mr. d. hall Orthographic Projection

2. Orthographic projection Orthographic projection is the most common method employed in engineering to produce the drawings giving details from which components are made.

3. Types of Orthographic projections Two angles are used in ORTHOGRAPHIC projections. These are known as FIRST ANGLE projection and THIRD ANGLE projection.   1 st Angle projection – commonly used through out Europe and the rest of the world.   3 rd Angle projection- commonly used in the USA.

4. Types of Orthographic projections In either First Angle or third Angle orthographic projection, the object which is to be drawn is placed in one of the angles formed by a vertical plane crossing a horizontal plane.

5. Planes A plane can be regarded as a flat surface. Orthographic projection depends upon the projection of views on to planes. Vertical Plane Horizontal Plane

6. Meaning of Orthographic If two planes meet at right angles to each other they are said to be “orthogonal “. The word orthographic is made up from the two words orthogonal and graphical. The word graphical refers to the drawings necessary for producing orthographic projections.

7. Angles formed by Vertical and Horizontal planes Look in this direction to see plan Look in this direction to see front view

8. Front View The object is then viewed looking at its front and what is seen is projected onto the vertical plane. The resulting drawing is called the “ front view”.

9. Plan The object is also viewed from above and what is seen is projected onto the horizontal plane. This drawing is called a “ plan”.

10. Intersection of Vertical and Horizontal planes 2nd Angle (not used) First Angle Third Angle 4th Angle (not used) Look in this direction to see plan Look in this direction to see front view (b) Vertical and horizontal planes as seen from arrow A (a) Pictorial view of Planes

11. First Angle Vertical Plane Horizontal Plane The vertical plane (VP) and horizontal plane (HP) are shown in their First Angle position. The two planes are at right angles to each other.

12. Object placed in 1 st Angle Front view Plan

13. Front view and Plan projected to VP and HP in 1 st angle Front view Plan Plan Front view The resulting front view on the VP and the Plan on the HP projected in the direction of the viewing

14. 1 st Angle projection Two plane swung to lie in the same flat surface showing the front elevation(view) and plan.

15. Two views 1 st Angle projection The resulting First Angle orthographic drawing giving two views of the OBJECT.

16. Three views 1 st angle projection Steps in obtaining three view Orthographic projection

17. Three views 1 st angle projection The object placed in position in the right angle formed by the two Vertical Planes and Horizontal Plane.

18. Three views 1 st angle projection The resulting Three Views projected in the direction of the viewing

19. Three views 1 st angle projection Three plane swung to lie in the same flat surface

20. Three views 1 st angle projection The resulting First Angle orthographic drawing giving the three views of the OBJECT

21. Three views 1 st angle projection The line joining the two VPs and HP are not shown. The PLAN lies exactly below the FRONT VIEW. The PLAN is in -line with the FRONT view. The END view is exactly on the right-side or left- side of the FRONT view. The END view is in-line with the front view. The END view on the right of the Front view is the view seen from the left of the front view. The British Standard symbol for 1 st Angle is included.

22. Multi-view 1 st angle projection END view looking from the right side of the object

23. Multi-view 1 ST ANGLE PROJECTION The resulting First Angle orthographic drawing with the END view looking from the right side of the front view.

24. Multi-view 1 st angle orthographic projection END view looking from the left side of the object

25. Multi-view 1 st angle orthographic projection The resulting First Angle orthographic drawing with the END view looking from the left side of the front view.

26. Four view orthographic projection LOOK IN THIS DIRECTION TO SEE END VIEW 1 LOOK IN THIS DIRECTION TO SEE END VIEW 2 LOOK IN THIS DIRECTION TO SEE FRONT VIEW LOOK IN THIS DIRECTION TO SEE PLAN

27. Four views placed in 1 st angle

28. Third Angle Orthographic Projection 3 rd Angle 3 rd Angle

29. Third Angle Projection (VP and HP) The vertical plane (VP) and horizontal plane (HP) are shown in their Third Angle position. The two planes are at right angles to each other.

30. HP swung to lie in same plane as VP To form a two dimensional surface, it is imagined that the HP is swung to lie in the same plane as the VP-as if the two planes were hinged together.

31. Isometric view of part of a Jig Clamp A pictorial drawing of the part of JIG CLAMP.

32. Object Placed in 3 rd Angle PLAN FRONT VIEW The Jig Clamp is placed in position in the right angle formed by the VP and HP. The two direction of viewing are shown by arrows

33. Front view and Plan projected on the VP and HP The resulting front view on the VP and plan on the HP projected in the direct direction of viewing

34. Front view and Plan projected on the VP and HP The two planes swung to lie in the same flat surface

35. Front view and Plan spaced on a drawing

36. 3 rd Angle Three View Projection A second VP is added to the VP and HP in their 3 rd Angle position

37. Placing the three planes into a two-dimensional flat surface 1 st Stage The second VP is swung through a right angle to lie in the same surface as the first VP.

38. Placing the three planes into a two-dimensional flat surface 2 nd Stage HP is swung through a right angle to lie in the same surface as the first VP.

39. Object placed in third angle The Object is placed in the angles formed by the two VPs and the HP. The three directions of viewing to obtain a front view, an end view and a plan are shown by arrows Front View Plan Left side End View

40. Front view, end view and plan projected from direction of viewing Resulting front view and end view on the two VPs and plan on the HP resulting from projecting from the three directions viewing.

41. Three views 3 rd Angle projection The three planes carrying the three views swung so as to lie in the same flat surface

42. Third Angle Orthographic Projection Third Angle Orthographic drawing giving the three views of the JIG CLAMP.

43. Object placed in third angle Right side End View Front View Left side End View Plan

44. 4 View 3 rd Angle Projection

45. 3 rd Angle Projection The Plan lies exactly above the Front View. The Plan is inline with the Front view The End view on the left of the Front view is the view seen as viewed from the left of the Front view. The End view is in-line with the Front view. The British Standard Symbol for 3 rd Angle projection is included.

46. THE PROJECTION SYMBOL (SIGN) The pictorial view of the frustum of a cone is shown. The front view and end view of the frustum is used to develop the orthographic projection symbol.

47. THE PROJECTION SYMBOL (SIGN) The frustum is placed in the 1 st Angle position.

48. THE PROJECTION SYMBOL (SIGN) The resulting Front view and End view of the frustum of the cone drawn in 1 st Angle projection.

49. 1 st ANGLE PROJECTION SYMBOL (SIGN)

50. THIRD ANGLE PROJECTION SYMBOL (SIGN)

51. CONSTRUCTION OF PROJECTION SYMBOL

52. Machine part