Ch.5 Multiview Drawings

1
Ch.5 Multiview Drawings
Objective Learn the rules for reducing a 3D
object onto a 2D multiview drawing and learn some
hints for visualizing a 3D object from a 2D
multiview drawing.

• Projection theory and multiview projection planes
  (5.1 through 5.3)
• 6 principal views (5.4)
• View selection rules (5.5)
• Fundamental views of edges and planes (5.6)
• Multiview representations (5.7)
• Multivew drawings visualization and summary (5.8
  5.10)
• ANSI standards for multiview drawings (5.9)

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Multiview Projection (5.1 through 5.3)

• See Fig. 5.1 to locate the multiview projections
  in the taxonomy of projects Projection ?
  Parallel projections ? Orthographic projections ?
  Multiview projections.

Object
Projection plane
Line of sight
3
Multiview Projection

• Multiview projection is an orthographic
  projection for which the object is behind the
  plane of projection, and the object is oriented
  such that only two of its dimensions are shown.

4
6 principal views (5.4)
Open up the glass box, producing the 6 principal
views.
5
US (ANSI 3rd-angle projection) vs. ISO (1st-angle
projection)
6
Steps to create a 3-view multiview drawing
7
View selection (5.5)

• Determine the best position of the object. Try
  to make the surfaces of major features either
  perpendicular or parallel to the projection
  planes.
• Define the front view. The front view should
  show the object in its natural or assembled
  state.
• Determine the minimum number of views is needed
  to completely describe the object so it can be
  produced.
• Once the front view is selected, determine which
  other views will have the fewest number of hidden
  lines.

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View selection (cont.)
Bad orientation
Good orientation
9
Fundamental views of planes (5.6)
Normal plane
Oblique plane
Inclinedplane
10
Fundamental views of edges
Oblique line
Normal line (true-length line)
Inclined line
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Normal, inclined, or oblique?
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Multiview representations (5.7)

• Many examples of multiview representations are
  given in this chapter. The best method to learn
  the art of multiview representation of 3D objects
  is to draw by yourself, with tools or freehand,
  the objects shown in Figures 5.47 through 5.68.
  We do not have time to cover all that are
  presented in the chapter. I present here only
  those that require a bit of explanations.

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Multiview representations (5.7)
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Multiview drawings visualization (5.8 5.10)

• Practice makes perfect. Without it, you will
  never learn this art of visualizing 3D objects
  from 2D multiview drawings.
• Projection studies
• Physical model construction
• Adjacent labeling
• Missing lines
• Vertex labeling
• Analysis of solids
• Analysis of surfaces

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Multiview drawings visualization (5.8 5.10),
cont.
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ANSI Standards for multiview drawings (5.9)

• Partial view

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ANSI Standards for multiview drawings (5.9)

• Revolution

Too busy
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ANSI Standards for multiview drawings (5.9)

• Revolution

• Removed view

Make the drawings easy to understand!