CE 101 Engineering Drawing

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Orthographic Drawing
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Multiview Projection

• Projection ? a view of an object
• Is a photograph enough to describe an object?
• A number of views, systematically arranged...

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Perspective Projection
Source, at a definite distance.
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Orthographic Drawing
Source, at an infinite distance
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Four Types of Projection
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Six Standard Views
TOP
REAR
RIGHT
LEFT
FRONT
BOTTOM
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Six Standard Views
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Six Standard Views
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Orthographic Drawing
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Orthographic Drawing
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Orthographic Drawing
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Unfolding the Glass Box
The Glass Box
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Top Right Side Views
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Third Angle Projection
A transparent picture plane is set up between
object and the station point of an observers eye.
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Third Angle Projection
Mitter line can only be used when the views are
placed equidistantly.
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First Angle Projection (Europe Asia)
F
R
The observer looks through the object to the
planes of projection.
D/2
D/2
D/2
D/2
T
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Views of Surfaces

• To effectively create and interpret multiview
  projections, you have to consider the elements
  that make up most solids
• SURFACES
• bounded by straight lines, or curves.

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Edge View
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True View
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Foreshortened View
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Normal Surface
Parallel to the plane of projection (true
shapesize)
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Perpendicular to a plane, but inclined or tipped
to adjacent planes. Edge vien on perp. Plane, fs
view on inclined planes
Inclined Surface
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Oblique Surface
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True length in adjacent planes
Point on perpendicular Plane.
Normal Edge
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Inclined Edge
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Oblique Edge
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Angles
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Vertices

• A corner or point, intersection of 3 planes

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Meaning of a Point

• A vertex
• Point view of an edge

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Meaning of a Line

• Visible or hidden
• An edge (intersection between 2 surfaces)
• Edge view of a surface
• Limiting element of a curved surface

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Hidden Lines
Dashed hidden lines are used to represent
features that would be hidden behind other
surfaces.
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Center Lines
Used to indicate symmetrical axes of circles
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Order of Drawing

• Block out the views
• Locate centerlines
• Start details and arcs first
• Draw dominant details
• Check your views

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Now Guess the object....
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So the Quiz Object....
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Guess the object....
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The object .... Is a rectangular prism
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Guess the object....
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The object ... Is a cylindrical prism
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Third Angle Projection...
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So The Object...
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THATS IT FOR TODAY!
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