1. MEMB113 07 Multiview Projection Drawing

2. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING Content Projection Theory Multi-view Projection [Planes | Lines] Multi-view [6 principle views | View placement] Projection angle [1 st angle | 3 rd angle] Detail drawing [1-view | 2-view | 3-view drawing] Creating multi-view drawing View selection Line convention Common feature in multi-view drawing

3. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.1 Projection Theory Engineering and technical graphics are dependent on projection methods 2 methods primarily used – Parallel: object positioned at infinity & viewed from multiple points on an imaginary line parallel to the object – Perspective: object position at finite distance & viewed from a single point Perspective Parallel

4. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.1 Projection Theory Projection theory comprises of the principles used to graphically represent 3D objects on 2D media Based on 2 variables: – Line of Sight (LOS): an imaginary ray of light between and observer’s eye and an object. Parallel – all LOS are parallel; perspective – all LOS start at a point – Plane of projection: an imaginary flat plane where the image created by LOS is projected.

5. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.1 Projection Theory Projections Parallel Projections Perspective Projections Oblique Projections Orthographic Projections Linear Perspective Aerial Perspective Multiview Projections Axonometric Projections

6. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.1 Projection Theory: Multi-view

7. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.1 Projection Theory Orthographic projection: a parallel proj. technique where the proj. plane is placed between observer and object and is perpendicular to the parallel lines of sight Changing view point

8. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.1 Projection Theory

9. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view projection Multiview projection is an orthographic projection for which the object is behind the plane of projection, and the object is orientated such that only two of its dimensions are shown. Orthographic projection – Front View Projection plane object

10. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view projection Multiview drawings – Employ multiview projection technique – Generally three views of an object are drawn – Each view is a 2D flat image

11. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view projection Top view Right side view

12. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view projection Multiview drawing of an object

13. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view: Lines Lines in multi-view projection

14. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view: Lines

15. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view: Planes

16. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.2 Multi-view: Planes

17. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.3 Multi-view: The 6 principal views The 6 principal views are the six mutually perpendicular views that are produced by six mutually perpendicular planes of projection Imagine an object is suspended in a glass box, the 6 sides become projection plane showing the six views

18. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.3 Multi-view: The 6 principal views The views are front, rear, top, bottom, left and right Front view – the 1 st to be established – Shows the most features – All other views are based on the orientation chosen for the front view

19. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.3 Multi-view: The 6 principal views The views are laid flat by “unfolding the glass box” This forms the basis of two important multiview drawing standard – Alignment of views – Fold lines Top, front and bottom views are all aligned vertically & share the same width dim. Rear, left, front and right side are aligned horizontally & share same height dim.

20. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.3 Multi-view: The 6 principal views Fold lines – are the imaginary hinged edges of the glass box – The fold line between the top & front views is labeled H/F – The distance from a point in front view to the H/F is the same as the distance from the corresponding point in the top view to the H/F fold line

21. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.4 Multi-view: View Placement The three-view drawing is the standard used in engineering, as normally other three principal views are mirror images The standard views – top, front & right The width dim. are aligned between the front & top view using vertical projection lines The height dim. are aligned between the front & right side view, using horizontal projection lines The depth dim. are aligned between top & right side view, using scale, miter line or compass

22. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.4 Multi-view: View Placement

23. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.4 Multi-view: View Placement The arrangement of views may vary as shown, where the top view is considered the central view Alternate view arrrangement

24. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.4 Multi-view

25. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.5 1 st - and 3 rd -angle projection There are two standard arrangement of all six views of an object – First-angle projection – Third-angle projection Each uses a different symbol The names are derived from the method used to view the object being drawn

26. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.5 1 st - and 3 rd -angle projection In first-angle projection, the object is placed in the first quadrant In third-angle projection, the object is placed in the third quadrant

27. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.5 1 st - and 3 rd -angle projection Brief rules 1 st angle projection3 rd angle projection View from above is placed underneath View from above is place above View from below is placed above View from below is placed below View from left is placed on right View from left is placed on left View from right is placed on left View from right is placed on right Symbols

28. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.5 1 st - and 3 rd -angle projection Third-angle projectionFirst-angle projection

29. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 One-view & two-view drawings One-viewTwo-viewThree-view One-view

30. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Two-view drawings Examples Two-view

31. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Two-view drawing Creating 2-view sketching 1 2

32. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 4 3 5.6 Two-view drawing

33. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING Decide: Projection angle, Location of view, Scale 5.6 Steps in creating multi-view drawing READ SKETCH DRAW Prepare paper -> Draw border -> Title block -> etc. Construct view (outline) -> Using thin pencil -> Measure & place view -> Project all views -> Final lining: hidden & centre lines (thin), arcs & circles (thick) Lining views -> Line in the rest of the lines -> Start from top left -> Construction lines may be left if thin enough Finish drawing -> Dimension, notes, etc. -> Finish off title block, etc. TOP FRONT SIDE height depth y y y y = (total length – height – depth)/3

34. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 3-view dwg Before start drawing, produce sketch on rough paper – Decide on front view and projection angle – Obtain the overall width, height and depth – Place the views (in block) – Determine approx. space between the views – Sketch the component, place dimensions

35. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Creating 3-view drawing (1) Drawing of border/frame and location of view (2) Light construction of view (inc. title block frame) (3) Lining in the views (4) Dimensioning and inserting of any subtitles and notes (5) Drawing title block, parts list and revision table

36. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Creating 3-view drawing (1) Draw border/frame, title block, etc. – Draw border, title block – Locating the view should be approx. in centre distance between view = (total length available – view length) / 3 – Drawing projection lines

37. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Creating 3-view drawing Projecting views

38. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Creating 3-view drawing (2) Light construction of the views  Draw light/thin horizontal & vertical lines accordingly for front view  Draw center lines and hidden lines as final  Draw top (or side) view  Project top view (or side) from front view using thin, light construction line  Draw side (or top) view  Project side view (or top) from front view and top (or side) view  All arcs and circles should be lined (final) at this stage

39. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Creating 3-view drawing (3) Lining in of the views – To darken all visible edges (lines that represent a hard edge) – Done using thick, black pencil (0.5mm, 2B) – Should be done systematically for 3 views – Start with horizontal line at the top of the top/plan view, working down the page using T-square – From left hand side, working across the page, line in all vertical lines, using T- square and set square – Projection lines may be left on the drawing if they are very light

40. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.6 Creating 3-view drawing ( 4) Write dimensioning, notes, annotation, etc. – Be aware of redundant dimensioning (5) Complete drawing by writing the rest of title block, parts list & revision table, and others.

41. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.7 View Selection 4 basic decisions (1) Determine the best position. The object must be positioned in such a way that the surface of major features are either perpendicular or parallel to glass planes. (1)

42. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.7 View Selection (2) Define the front view. Should show the object in natural state and show most features. (2)

43. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.7 View Selection (3) Determine the minimum number of views needed to completely describe the object. (4) Determine other views that have fewest number of hidden lines (4) (3)

44. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.8 Line convention Hidden lines Hidden features Centre lines

45. adzlyanuar © 2004 MEMB113 | Dept. of Mechanical Engineering | UNITEN | 2005 07 MULTIVIEW PROJECTION DRAWING 5.8 Line convention Hidden lines Drawing conventions for hidden lines

46. End of chapter [07] References: - Engineering Drawing, A.W. Boundy, McGraw-Hill, 2000 - Fundamentals of Graphics Communication 3rd Edition, Gary Bertoline & Eric Weibe, McGraw-Hill