1. Engineering Graphics 2018-19-I
Lecture 25
TA101A
Engineering Graphics I By
Dr. Mukesh Sharma
Professor
DEPARTMENT OF CIVIL ENGINEERING
INDIAN INSTITUTE OF TECHNOLOGY KANPUR
KANPUR , INDIA

2. (1)
Sections: A10, A11, A12 and A14
Date: (Saturday)
Time: 10:00 AM - 01:00 PM
Venue (for A10, A11, A12): New Core Lab, CC01 and CC03
Venue (for A14): AutoDesk Lab, Drawing Hall
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(2)
Sections: A1, A2 and A3
Date: (Monday)
Venue: New Core Lab, CC01 and CC03
_________________________________________ 3)
Sections: A7, A8 and A9
Date: (Thursday)
(4) Sections: A4, A5, A6 and A13
Date: (Saturday)
Time: 2:00 PM - 05:00 PM
Venue (for A4, A5, A6): New Core Lab, CC01 and CC03
Venue (for A13): AutoDesk Lab, Drawing Hall
______________________________________________
The TAs/Tutors will grade your work on the spot after completion of Lab.
Do not delete your work until it is graded and you have consent from
TAs/Tutors to delete it.
If you want to save your drawing and keep it, you can do so.

3. All Objects are made of points, lines and planes
To develop the surface you need TL of lines and TS of planes

4. Develop the surface of the object so that it is constructed
Developed surface is cut from sheet, paper, leather
Object surface is made of lines, planes and points
Idea is to develop these surfaces in True Shape.
Most important points are find TL of line and TS of planes
Remember we want the magnitude of line and plane – for this we do not care about the orientation or it FV and TV.
Normally Auxiliary plane method is not used – as you need information for so many lines and many auxiliary views.

5. Development of Surfaces - Example

6. How to open – there is a convention
It should be inside layer up
Developed surface is shown on flat surface seen directly by the observer

7. True length of line by revolutionYH X
Path of
Revolution XH
YHR
Axis H F XF F ӨR Y O TL YR H
TL Axis ӨH YF
YFR
OBSERVATION
If axis is perpendicular to the plane, the hypotenuse of triangle like XOYR will
always give the TL of the line. Or, if perpendicular and base are known so is the TL.

8. Development of Truncated Prism3 4
Measuring line
and bend line 4 4 2
Lateral edge
3,5 3 5 1 6
2,6 2 1 1 1
Seam
line A A A D
C,E
B,F B F C E D E C B F A A
Right section
and base
Stretchout or girth
C,3
B,2 A D F E
D,4
A,1
Lap seam
Lateral surface
E,5
F,6
Lay off the perimeter of the base on line AA

9. Development of Truncated PyramidET FT A1 F1
Seam line LT E1 KT N1 MT DT OT NT AT L1 D1 JT HT K1 CT BT C1 OF M1 J1 O1 H1 MF B1 JF JR HF HR N1
Development of Truncated Pyramid A1 NF
We should find TL of truncated edges.
Is ON or NA see in TL somewhere?
Yes in FV. Mark it on developed surface
How to get OH in TL?
Rotate OH so that it is parallel to hinge line and project it in FV
Repeat process for OJ. OM is is already in TL FV.
Transfer these on developed surface AF DF

10. Development of Irregular PyramidCr Dr D1 Or Br Ar OF O1 C1 B1 AR
BFCF
AFDF A1

11. Development of an Oblique Pyramid
Seam line O1 Cr Dr A1 Or
Bend line Br Ar D1 B1 Or
Stretchout or girth C1
Axis
BRCR
AR,DR
Soldered lap seam
CRBR
ARDR

12. Development of an Truncated Cylinder* * * * * * * * * * * *