Page 122 - CITS - ED - Mechanical

ENGINEERING DRAWING - CITS

Fig 11

Exercise 7.12

Draw the development of the lateral surface of the frustum of a square pyramid as positioned. (Fig 12a)
• Draw the front view and plan of the pyramid. (Fig 12b) None of lines in these views show the true length of
slant edge.

• Transfer OP in plan to xt in front view. Join o't' by straight line. o't' is the true length of slant edge.
• With `O' as centre draw the development of whole pyramid. (Follow the steps of the exercise 14.10)
• With `O' as centre set off OA, OB, OC, OD & OA equal to O'U' in front view. (Fig 12c)
• Join AB, BC, CD, DA. Surface bounded by ABCDATSRQP is the development.

Fig 12

Exercise 7.13
Draw the development of the lateral surface of a funnel as positioned. (Fig 13)
• The parts (A & B)of the funnel are in the shapes of frustum of cones.

• Development of cone and frustum of cone are already dealt in earlier exercises. Follow the previous procedures
and draw the developments of both parts A and B.

109
CITS : Engineering Drawing (Mechanical) - Exercise 7