1. Changes to assessment:
Engineering, D&T, PDT Ignore section (b) and (c) week 4
ATI see new sheet

3. Orthographic Projection & Sectional Views
Week 2
Orthographic Projection & Sectional Views

4. First Angle
Third Angle
Sectional views

6. Plan View
End Elevation
(Right)
Front Elevation
End Elevation
(Left)

7. First Angle Plan View End Elevation (Left) End Elevation (Right)
Front Elevation

8. Linework
Outlines
Construction
Hidden
Centre
Section

9. First Angle

10. Third Angle Plan View End Elevation (Left) End Elevation (Right)
Front Elevation

11. Note: six views in total may be derived from any shape
only draw a maximum of three

12. Symbols
Derived from a truncated cone:

15. Page Layout:

16. Construction:

17. Construction:

18. Construction:

19. Construction:

20. Construction:

21. Construction:

23. Sectional Views

24. Background
Produced when one imagines the component to be cut through a defined cutting plane

25. Cutting plane and direction of viewing is defined on a non-sectional view using chain lines thickened at each end
The direction of viewing indicated as shown by arrows

26. Reasons for sectioning
to illustrate internal features
to reduce number of hidden detail lines
to allow internal features to be dimensioned
to show relative position of parts in an assembly

27. Cutting plane indicated with 45º (or other), equidistant 4mm hatching

28. Two adjacent parts hatched in opposite directions
More than two parts then different spacing used (smaller parts usually have closer hatching)
Large areas of hatching usually not filled in

29. Parallel section planes have no effect on hatching

30. Parallel section planes have no effect on hatching

31. Sectioning exceptions
Some shapes are not sectioned even if they lie in the sectioning plane. The following shapes when cut longitudinally are not sectioned:
Shafts, keys, rivets, ribs, pins, bolts, spokes, nuts, webs, washers

32. Shaft
Web

34. Orthographic Sections

35. Section of an Assembly

36. Omit hidden lines from sectional views of a component!