1. CHAPTER 8 Multiviews

2. Learning Objectives Select appropriate views for presentation Prepare single- and multiview drawings Create detail views Draw view enlargements

3. Learning Objectives Establish runouts Explain the difference between first- and third-angle projection Create multiview drawings using first- and third-angle projection Prepare formal multiview drawings from an engineer’s sketch and actual industry layouts

4. Orthographic Projection System for drawing and dimensioning complex three-dimensional items Changes physical objects and three- dimensional ideas into two-dimensional drawings Uses descriptive geometrydescriptive geometry

5. Orthographic Projection Lines of sight perpendicular to plane of projection Surface of the object parallel to the plane of projection: Surface appears true size and shape Surface of the object not parallel to the plane of projection: Surface appears foreshortened, or shorter than true length True geometry view

6. Orthographic Projection

7. Multiviews Multiview projection Multiview drawing The result of multiview projection Represents the shape description of the object

8. Multiview Standards ASME ASME Y14.3, Multi and Sectional View Drawings ISO Alternate view definition systems

9. The Glass Box Visualization Method Sides of the glass box are planes of projection Six total sides, or views: FRONT TOP RIGHT-SIDE LEFT-SIDE BOTTOM REAR

10. The Glass Box Visualization Method Sides unfold at hinge lines, also known as: Fold lines Reference lines

11. The Glass Box Visualization Method Arranges views in third-angle projection Projection techniques: 45°mitre line Arcs Transfer

12. Third-Angle Projection Primary multiview projection method Common in the United States Identified by the third-angle projection symbol Angle of projection block near the title block

13. First-Angle Projection Common in countries other than the United States Identified by the first-angle projection symbol Angle of projection block near the title block

14. Third-Angle versus First-Angle Projection

15. View Selection Six views possible: FRONT TOP RIGHT-SIDE LEFT-SIDE BOTTOM REAR

16. View Selection Seldom necessary to use all six views Only draw the number of views necessary to completely described the object Front view usually most important Establishes other views Always one dimension common between adjacent views

17. Selecting the Front View Represent the most natural position of use Provide the best shape description or most characteristic contours Have the longest dimension Have the fewest hidden features Be the most stable and natural position

18. Selecting the Front View

19. Selecting Two or Three Views Most contours Longest side Least hidden features Best balance or position

20. Two-View Drawings

21. One-View Drawings Thickness identified in a note or title block All shape and dimensional information in one view If in doubt, drawn the adjacent view

22. Partial Views Symmetrical objects drawn in limited space Simplify complex views Break lines show that a portion of the view is omitted

23. Detail View Increases the scale of part of a view Use when detail cannot be clearly dimensioned due to: Drawing scale Complexity

24. Removed Views Out of normal arrangement with other views Avoid when possible, but may be necessary when: Limited space Enlarge the view Can appear on a different sheet from where the view is taken if necessary

25. Viewing Plane Lines for Removed Views

26. Arrow Method for Removed Views

27. Views with Related Parts

28. Rotated Views Rotated from normal alignment with other views Avoid when possible, but may be necessary when: Limited space Enlarge the view Keep all views on one sheet Angle and direction of rotation under the view title ROTATED 90°CW ROTATED 90°CCW

29. Projecting ChamfersChamfers Slanted edge or a line

30. Projecting Circles Line of sight perpendicular to a circular feature Feature appears round Circle projected onto an inclined surface View is elliptical in shape

31. Projecting Arcs

32. Projecting Rounded Corners Represented as a contour only Fillets Rounds Break corners

33. Projecting Rounded Curves and Cylindrical Shapes Phantom lines sometimes used to accent rounded feature

34. Runouts

35. Line Precedence Object lines take precedence over hidden lines and centerlines Hidden lines take precedence over centerlines Cutting-plane lines take precedence over centerlines

36. Line Precedence

37. Glossary Break corner A sharp corner with a slight relief. Chamfer The cutting away of the sharp external or internal corner of an edge. Descriptive geometry A drafting method used to study 3-D geometry with 2-D drafting applications where planes of projections analyze and describe the true geometric characteristics.

38. Glossary Fillets Slightly rounded inside curves at corners, generally used to ease the machining of inside corners or to allow patterns to release more easily from castings and forgings. Multiview drawing Represents the shape of an object using two or more views. Multiview projection Establishes views of an object projected upon two or more planes of projection by using orthographic projection techniques.

39. Glossary Multiviews Two-dimensional views. Orthographic projection Any projection of the features of an object onto an imaginary plane called a plane of projection. Related part method Showing a part or parts that are next to the part being detailed.

40. Glossary Rounds Rounded outside corners that are used to relieve sharp exterior edges. Runouts The characteristics of intersecting features with circular objects are projected in multiview to the extent where one shape runs into the other. True geometry view The view that shows the actual shape of the object.