1. Concordia University Mechanical Engineering Drawing MECH 211/M
Lecture #4; Chapters 8 and 19
Dr. John Cheung

2. Quiz: Show the true shape of the inclined surface.

3. Quiz
Question: Show the true shape of the inclined surface.

4. Assignment #1 Fig. 4.8

5. Assignment #1 Fig. 4.32

6. Assignment #1 Fig. 4.53

7. Assignment #1 Fig. 4.58

8. Dihedral Angle
T.L. Line 1-2
Dim. D from front view
Point view 1 & 2.

9. Oblique Surface – True Shape

10. Oblique Surface – True Shape

11. True Length Lines To draw a true length line:
When foreshortened - use a fold-line parallel the line
When viewed as a point - draw any view perpendicular
When line is fully in a plane – it is true length

12. Surfaces in Edge View To draw a surface as an edge view:
Choose an edge and draw it so that it is true length
Draw a view that is perpendicular to the true length line

13. True Shape of a Surface
To determine the true shape and size of a surface:
Draw the surface as an edge
Draw a view that is perpendicular to the edge view
A surface that is parallel to the view plane is true shape
All of the lines in the plane are true size
Planes that are orthogonal to this plane are true

14. Points

15. Points – In Adjacent View

16. Multiple Points - Lines

17. Line in Adjacent View

18. Lines in Adjacent Views

19. True Length of Oblique Line

20. True Length Line

21. True Length Line

22. True Length Line

23. True Length Line

24. True Length Line

25. True Length Line

26. Bearing of A Line Angle between line and North in Horizontal plane
North is normally up on drawing
Angle is less than 90°

27. Bearing of A Line – Orthographic Projection

28. Slope of a Line
The angle of the line and the Horizontal plane

29. Slope of a Line

30. Slope of a Line

31. View a Line as a Point

32. Line Types
Skew lines: non intersecting, non-parallel and not coincident
Intersecting lines: one common point
Parallel lines: no common points
Coincident lines: overlapping – all points are common

33. Intersecting Lines

34. Skew Lines

35. Skewed Lines

36. Parallel Lines

37. Not Parallel Lines

38. Parallel Lines Passing Through a Point

39. Parallel Lines Passing Through a Point

40. Distance Between Parallel Lines

41. Perpendicular Lines
A 90° angle appears in true size in any view showing one leg in true length

42. In Class Assignment
Figure 19.33