ES 101 Engineering Graphics Gaurav Srivastava Assistant Professor Civil Engineering (gauravs@iitgn.ac.in) Fall 2017

Last time Projection Orthographic projection

Six principal views on glass box

Multi-view Projection

Comparison of Various Projections Advantage Disadvantage Isometric view drawings Easy to understand 3D representation of objects Shape and angle distortion Multi-view drawings Accurate representation of shape and size Requires practice in drawing and reading Perspective view drawings Realistic representation of human vision Shape, size and angle distortion http://upload.wikimedia.org/wikipedia/commons/5/5f/Camera_focal_length_distance.gif ES101: Lecture 4 (4 September 2014)

Angle of Projection – Conventions 1st angle of projection Object in front of plane 3rd angle of projection Object behind plane Right Profile Plane Frontal Plane Second Quadrant First Quadrant Horizontal Plane Third Quadrant Fourth Quadrant

First Angle of Projection

Third Angle of Projection

First Angle of Projection

Third Angle of Projection

Third Angle of Projection

Projection Symbol 1st angle projection 3rd angle projection Front View Left View Front View 1st angle projection 3rd angle projection Left View Front View

Example: Angles of Projection First Angle of Projection Third Angle of Projection

Necessary Views

Necessary Views

Two View Drawings

Two View Drawings

Two View Drawings Choosing between two views prefer the one with fewer number of hidden lines

Two View Drawings Choosing between two views prefer the one that fits better on the drawing sheet

Two View Drawings

One View Drawings A single view supplemented by a note or lettered symbols for relatively simple object 0.25 mm thick

One View Drawings Shafts, bolts, screws, and similar parts are generally represented by single views

Alignment of Views

Practice problem Sketch 3rd angle orthographic projection 5 15 6

Practice problem Sketch 3rd angle orthographic projection