Lpu mechanical engineering sem 1 class ppt notes

1. ENGINEERING GRAPHICS
Topic:
Projection of Lines
UNIT- 2

2. SIMPLE CASES OF THE LINE
1. A VERTICAL LINE ( LINE PERPENDICULAR TO HP & // TO VP)
2. A VERTICAL LINE ( LINE PERPENDICULAR TO VP & // TO HP)
3. LINE PARALLEL TO BOTH HP & VP.
4. LINE INCLINED TO HP & PARALLEL TO VP.
5. LINE INCLINED TO VP & PARALLEL TO HP.
STUDY ILLUSTRATIONS GIVEN ON NEXT PAGE
SHOWING CLEARLY THE NATURE OF FV & TV
OF LINES LISTED ABOVE AND NOTE RESULTS.
PROJECTIONS OF STRAIGHT LINES.
INFORMATION REGARDING A LINE means
IT’S LENGTH,
POSITION OF IT’S ENDS WITH HP & VP
IT’S INCLINATIONS WITH HP & VP WILL BE GIVEN.
AIM:- TO DRAW IT’S PROJECTIONS - MEANS FV & TV.

3. X
Y
X
Y
b’
a’
b
a
a b
a’
b’
B
A
TV
FV
A
B
X Y
H.P.
V.P.
a’
b’
a b
Fv
Tv
X Y
H.P.
V.P.
a b
a’ b’
Fv
Tv
For Tv
For Tv
Note:
Fv is a vertical line
Showing True Length
&
Tv is a point.
Note:
Fv & Tv both are
// to xy
&
both show T. L.
1.
2.
A Line
perpendicular
to Hp
&
// to Vp
A Line
// to Hp
&
// to Vp
Orthographic Pattern
Orthographic Pattern
(Pictorial Presentation)
(Pictorial Presentation)

4. A Line inclined to Hp
and
parallel to Vp
(Pictorial presentation)
X
Y
A
B
b’
a’
b
a


A Line inclined to Vp
and
parallel to Hp
(Pictorial presentation)
Ø
a b
a’
b’
B
A
Ø
X Y
H.P.
V.P.
T.V.
a b
a’
b’

X Y
H.P.
V.P.
Ø
a
b
a’ b’
Tv
Fv
Tv inclined to xy
Fv parallel to xy.
3.
4.
Fv inclined to xy
Tv parallel to xy.
Orthographic Projections

6. X
Y
b’
a’
b
a
A
B
For Tv
Note:
Fv & Tv both are
// to xy
&
both show T. L.
1. A Line // to HP & // to VP
Q: A line AB = 50 mm long. Endpoints A & B are 30 mm above HP & 20 mm in front
of VP. Draw Projections.
ANSWER
(Pictorial Presentation)

7. A Line inclined to HP and parallel to VP
Q: A line AB = 50 mm long is inclined to HP at 30 degree. Endpoints A & B are
20 mm in front of VP. Endpoint A is 30 mm above HP. Draw projections. And
also draw trace of the line.
X
Y
A
B
b’
a’
b
a


2.
Fv inclined to xy
Tv parallel to xy.
(Pictorial Presentation) ANSWER

8. A Line inclined to VP and parallel to HP
Q: A line AB = 50 mm long is inclined to VP at 45 degree. The endpoints A & B
are 30 mm above HP. Endpoint A is 20 mm in front of VP. Draw projections.
Also locate the trace of the line.
Ø
a b
a’
b’
B
A
Ø
Tv inclined to xy
Fv parallel to xy.
3.
ANSWER
(Pictorial Presentation)

9. X
Y
b(a)
b’
a’
A
B
TV
FV
For Tv
Note:
Fv is a vertical line
Showing True Length
&
Tv is a point.
4.
A Line perpendicular to HP & // to VP
Q: A line AB = 50 mm long is perpendicular to HP. The end points A & B are 20
mm in front of VP. Endpoint A is 15 mm above HP. Draw Projections & also
locate the trace of the line.
ANSWER
(Pictorial Presentation)

10. 5.
A Line perpendicular to VP & // to HP
Q: A line AB = 50 mm long is perpendicular to VP. The end points A & B are 20
mm above HP. Endpoint A is 15 mm in front of VP. Draw Projections & also
locate the trace of the line.

11. 6. A Line in VP
Q: A line AB = 50 mm long is in VP. The end points A & B are 30 mm above HP.
Draw Projections.

12. 7. A Line in HP
Q: A line AB = 50 mm long is in HP. The end points A & B are 20 mm in front of
VP. Draw Projections.

13. THANKS