Orthographic Projection, multi-view drawings, & Precedence of lines

1. Orthographic Projection, multi-view drawings, & Precedence of lines North Carolina State University Spring 2013

2. What You Will Learn: • Define Orthographic Projection. • Correctly label the placement of the six standard views of an object drawing. • Identify which views are needed when creating a multi-view drawing of an object. • Create a multi-view drawing with the correct views from a given object. • Identify different types of lines used for drafting. • Identify which line types have precedence over others. • Create multi-view drawings using different line types.

3. Section 1:Orthographic Projection & Multi-view Drawings

4. Orthographic Projection • Orthographic Projection: (n) a parallel projection technique that creates a 2-D image of 3-D objects or structures on an image plane perpendicular to the lines of sight. • In The U.S. we use a method called Third Angle Projection • Used to represent all aspects of a 3-D object by only using 2-D drawings

5. Glass Box Method • View each object as if it were in a glass box. • When unfolding the box you have the 6 views of projection.

6. The 6 Views of Projection • Top – Looking down on an object (birds eye view) • Front – ALWAYS the most descriptive • Right Side – To the right of the front view • Bottom – opposite of the top • Left Side – opposite of the right • Back – opposite of the front

7. Proper Layout of a Multi-View • Each view has a specific location as to where it is placed in reference to others.

8. Creating a Multi-View Drawing • Only use the views necessary to visualize the full object. (Typically: top, front, right side) • Sometimes only two views are necessary such as when drawing a cylinder

9. Examples

10. Examples INCORRECT CORRECT

11. Guided Practice: • Create a multi-view drawing of this object. • Label each view of your drawing.

12. Solution:

13. Guided Practice: • Create a multi-view drawing of this object. • Label each view of your drawing.

14. Solution:

15. Independent Practice: • Create a multi-view drawing of the following two objects. • Label each view of your drawings.

17. Solution 1:

18. Solution 2:

19. Section 2:Line Types &Precedence of lines

20. Visible Lines: • Thick and Bold • Often called construction lines or object lines • Used for the outer edges and visible features of an object.

21. Hidden Lines: • Thin, dashed line • Used to show hidden features within an object which can not be seen from the outside of the object.

22. Center Lines: • Thin lines with alternating long and short dashes. • Show the center of both visible and hidden circular features such as holes, cylinders, etc.

23. Precedence of Lines • Precedence of Lines: The order in which different line types appear in an drawing based on importance.

24. Precedence of Lines:

25. Example:

26. Guided Practice: • Create a multi-view drawing of this object. • Label each view of your drawing. • Include visible, hidden, and center lines

27. Solution:

28. Guided Practice: • Create a multi-view drawing of this object. • Label each view of your drawing. • Include visible, hidden, and center lines

29. Solution:

30. Independent Practice: • Create a multi-view drawing of the following two objects. • Label each view of your drawings. • Include visible, hidden, and center lines

32. Solution 1:

33. Solution 2: