1 / 55

Multiview Sketching & Projection: Understanding Orthographic Projection & Essential Views

Learn about orthographic projection and how to create the necessary views to accurately describe an object. Explore the glass box method and understand the arrangement of views for third angle projection.

cindyvaldez
Download Presentation

Multiview Sketching & Projection: Understanding Orthographic Projection & Essential Views

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 5 Multiview Sketching & Projection Print handouts Select File, Print Edit the following selections to read: Select the OK button

  2. Orthographic Projection • A system of drawing views of an object using perpendicular projectors from the object to a plane of projection (I.e. paper)

  3. Six Standard Views • Top, front, right side, left side, back and bottom • Front • Usually shows most detail • If applicable – should show object in operating condition (I.e. car)

  4. View Placement (3rd angle projection) • Front view usually shows the most detail Projection Lines • Why must views be arranged so that they align? • To make it possible for someone to interpret the drawing.

  5. Revolving an Object to Produce the Six Basic Views

  6. The Glass Box Metaphor • Imagine that the object you are going to draw is positioned inside a glass box, so that the large flat surfaces of the object are parallel to the walls of the box. • 2 horizontal planes • 2 frontal planes • 2 profile planes • From each pointon the object, imagine a ray, or projector perpendicular to the wall of the box forming the view of the object on that wall or projection plane. • 2 horizontal planes (top and bottom views) • 2 frontal planes (front and back views) • 2 profile planes (right and left side views)

  7. Projection of an Object

  8. Projection of an Object

  9. Unfolding the Glass box • For Third Angle Projection (the method in the U.S.) • Imagine that the walls of the box are hinged and unfold the views outward around the front view. • This will give you the standard arrangement of views for 3rd Angle Projection which is used in the US, Canada, and some other countries.

  10. Third Angle Projection: Symbol forthird angle projection shown on dwg Third angle projection Standard for USA, Canada and our class! First Angle Projection: First angle projection Primarily used in Europe and Asia! Symbol forfirst angle projection

  11. Glass Box Method

  12. DEMO • If a point, line or plane is in one view, it must be in all the views.

  13. Hidden Lines

  14. Precedence of Lines • When visible lines, hidden lines and center lines coincide remember: • Visible lines take precedence over hidden lines • Hidden lines take precedence over center lines, For example: Figure 5.32

  15. Example • Do Hands-On 3 together • Need • HB pencil • Engineering Calculation Paper • Model • Instructions (Sept. Schedule of Assignments in Angel) • Follow instructions • Remember specs for the border & title block are included in the Penn State Erie Graphics Standards and in Handouts folder in Angel • Label • Views – TOP, FRONT, etc.

  16. Hands-On 4 • Instructions on the web

  17. Chapter 5 Multiview Sketching & Projection Part 2

  18. Necessary Views • A sketch or drawing should only contain the views needed to clearly and completely describe the object. Choose the views that show the shape most clearly, have the fewest hidden lines, and show the object in a usual, stable, or operating position. One view drawing of a shim One view drawing of a connecting rod

  19. Reference Line or Fold Line 3 Views - Most Common Three views necessary? Which view could be eliminated? Top 45° Views? Depth Planes? Dimensions? H F Width Depth Projection Lines Height F P Front Right Side

  20. Transferring Dimensions • Mitered System • Dividers or Scale

  21. This will be the left edge of the right side view clear space Mitered System • Determine spacing necessary between the front and right side views. • For example, when dimensioning, more space is needed between the views.

  22. Bottom edge of the top view Intersection Left edge of the right side view clear space Mitered System • Extend a projection line from the bottom edge of the top view and one from the left side of the right side view until they intersect.

  23. From point of intersection 45º Mitered System • Extend a 45° angled line from the point of intersection.

  24. Mitered System cont’d. 2 1 3 4 • Project additional points, surface by surface. 1 1 3

  25. Mitered System cont’d. 2 1 8 7 6 3 5 4 • Project additional points, surface by surface.

  26. Mitered System cont’d. 2 1 8 7 6 3 5 4 • Draw the view locating each vertex of the surface on the projection and miter line.

  27. Dividers or Scale • With folding lines • Without folding lines

  28. Hidden Lines

  29. Also Review • PENN STATE ERIE DRAFTING STANDARDS

  30. Chapter 5 Multiview Sketching & Projection Part 3

  31. Review Hidden Lines

  32. Surface Identification

  33. View Identification

  34. Configuration Rule NORMAL SURFACE Plane is shown true shape and size. In other words, parallel to one of the principal planes. EDGE EDGE TS SURFACE B

  35. EDGE EDGE Configuration Rule INCLINDED SURFACE Surface is perpendicular to one plane and will show as an edge on that plane. And the surface is tipped, or inclined, to adjacent planes. The surfaces in these views are foreshortened.

  36. EDGE TS EDGE NORMAL PLANE Configuration Rule OBLIQUE PLANE Surface is not parallel or perpendicular to any principal plane. ? PLANE EDGE

  37. Configuration Rule ? PLANE • Is this one correct?

  38. Points, Lines & Planes • If all else fails, • Break the object down to simpler shapes • Locate the height, width and depth of each point.

  39. Exercise

  40. Chapter 5 Multiview Sketching & Projection Part 4

  41. 1/8” DASH 1/16” GAP ¾” – 1-1/2” LONG Center Lines Thin dark line Purpose of a center line? To show location of a hole, arc, cylinder, etc.

  42. Center Lines Extend center line ¼” past the hole HOW MANY CENTER LINES MISTAKES? Extend center line ¼” past the hole

  43. Center Lines • ¼” past the end of the hole and/or cylinder End of cylinder End of hole End of hole

  44. 1/16” GAP Precedence of Lines ¼” FROM END OF HOLE HIDDEN LINES TAKE PRECEDENCE OVER CENTER LINES OBJECT LINES TAKE PRECEDENCE OVER HIDDEN LINES

  45. If longer than 1-1/2” add a dash in the middle INCORRECT Center Lines 1/16” gap

  46. Projection of an Object Fillets and Rounds: Self locating, so do NOT add center lines, but do draw where sharp corner would be.

  47. Projection of an Object Why? POOR PRACTICE PREFFERED Adds clarity

  48. Projection of an Object POOR PRACTICE PREFFERED PRACTICE

  49. Runout POOR PRACTICE PREFFERED PRACTICE Projection of an Object

  50. Chapter 5 Multiview Sketching & Projection Part 5

More Related