Engineering Graphics 2018-19-I Lecture 8 TA101A Engineering Graphics 2018-19-I By Dr. Mukesh Sharma Professor DEPARTMENT OF CIVIL ENGINEERING INDIAN INSTITUTE OF TECHNOLOGY KANPUR KANPUR-208016, INDIA

Make-up Class on Saturday, September 01 at 12:10 PM in L20

Oblique Projections Produces 3-D views Process virtually opposite to isometric view Do not look perpendicular through projection plane Object is not rotated Object remains with a major face parallel to projection plane Now one looks the projection plane with an oblique angle Axes of height and width remains at 90 degrees Axis of depth can vary in angle, ø What is specialty of oblique projection. Isometric S R U 35 to 450 Oblique

DRAW AN OBLIQUE DRAWING 1.draw a rectangle – overall width and height of the object 2. extend parallel lines from each corner of the box back at an angle 3. mark the extension lines at a point equal to the depth of the object. 4. connect the depth of lines to form a box. 5. add any details such as holes, notches, onto the front view (True size & True Shape). 6. extend the details the depth of the object. 7. complete sketch by darkening in the object

40 50 90 65 25 R15 300

300 X z y 90 50 65 R15 40 25 90 50 40 300

600 450 C 300 A 900 B 25 Given (a) Receding axis is usually Drawn at 300, 450 or 600 With the horizontal Construct area (b) 450 Draw the front face (c) Parallel Construct receding surface (d) Draw arc on the rear face (e) 25 Parallel Heave the outline (f)

50 10 20 R 26 50 20 70 Ø 26

50 70 20 10 ø26 R26 10 20 20 R26 50 20 70 Ø 26

How to select front face?

A B C All Oblique views. Which one is preferred face?

A B How to select front – contd…

Oblique Projections DOP not perpendicular to view plane n CGR Cavalier (DOP at 45 ) ° Cabinet (DOP at 63.4 ) k 24

List differences in Isometric and Oblique views

A CABINET B CAVALIER

Parallel Downward receding direction