engineering graphics(orthographic projection)

ENGINEERING GRAPHICS

PROJECTION

Tuesday, April 11, 2023 1

VISHAL SRIVASTAVA B.Sc.(Hons) CS 115138

Projections (1)Projections transform points from n (here, n

= 3) dimensional space into a space of dimension less than n (here, n = 2)

Points to be considered, Location of object Location of observer Plane of projection Projectors


Projections (2)


Perspective Projections


Parallel Projections


Parallel ProjectionsProjectors are parallel to

each other but not perpendicular to projection plane

Effective in pictorially representing objects


Axonometric

The object is tilted and all three coordinate axes are visible in any one view

(PP projection plane)


Orthographic (Orthogonal)

The object is at rest and two coordinate axes are visible in any one view

(PP projection plane)


Multiview ProjectionsFront surfaces of object is parallel to plane of

projection

Projectors or line of sights are perpendicular to projection plane

Projectors are parallel to each other and originate from any point on object


Multiview Projections


The six views


Angles

First angle projection – European SystemThird angle projection – American System


First Angle Projection


First Angle Projection 1

How to draw plan and elevation?


First Angle Projection 3

Points to remember:

• The ‘front view’ (or elevation) is the view with maximum information.

•The ‘plan’ is below the ‘elevation’ (in projection).

•The ‘end view’ is placed on the right if viewed from left side of object and on the left if viewed from right side.

•‘End view’ and plan face inwards from ‘elevation’.


engineering graphics(orthographic projection)

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