Textbook of Engineering Drawing, Second Edition

5.10 Textbook of Enginnering Drawing------------------

y X VP a'

HPi\lU

Y

0

I a

X }.-'/ A,a H

I

I a

I y..~

I ....-

I /' /'

[,.../'

Fig. 5.10

Tv

a a'

A

a' c

....

....^0 y VP

X Y

HP a

Fv

X a

Fig. 5.11

2. Looking at the pictorial view from the top, point a is on V.P and its view lies on xy itself. The
   top view a does not lie on the H.P. So in this case the H.P need not be rotated. Therefore
   mark a on xy on the projector drawn from al.
   Problem : A Point B is 30 mm above HP and 40 mm behind v.p Draw its projection.
   Solution: (Fig.5.I2) The point B lies in the IT Quadrant


3. It is 30 mm above H.P and bI is the front view ofB and is 30 mm above xy.


4. Point B is 40 mm behind v.P. and b is the top view ofB which is 40 mm behind xy.


5. To obtain the orthographic projections from the pictorial view rotate H.P by 90° about xy as
   shown in Fig.5.12a. Now the H.P coincides with v.p and both the front view and top view
   are now seen above xy. b on the H.P will trace a quadrant of a circle with 0 as centre and ob
   as radius. Now b occupies the position above o.