NOTATIONS

1
NOTATIONS
FOLLOWING NOTATIONS SHOULD BE FOLLOWED WHILE
NAMEING DIFFERENT VIEWS IN ORTHOGRAPHIC
PROJECTIONS.
OBJECT POINT A
LINE AB
ITS TOP VIEW a
a b
ITS FRONT VIEW a
a b
ITS SIDE VIEW a
a b
2
2nd Quadrant
VP
1ST Quad.
2nd Quad.
F.V.
1st Quadrant
Y
Observer
HP
X Y
X
3rdQuadrant
Observer
4th Quad.
3rd Quad.
4th Quadrant
3
POINT A IN 1ST QUADRANT
POINT A IN 2ND QUADRANT
Point A is Placed In different quadrants and
its Fv Tv are brought in same plane for
Observer to see clearly. Fv is visible as it
is a view on VP. But as Tv is a view on Hp, it
is rotated downward 900, In clockwise Direction
(in 1st quadrant).The In front part of Hp comes
below xy line. The HP behind the Vp is also
rotated clockwise, and therefore comes above the
xy line. Observe and note the process.
a
A
A
a
a
a
a
a
a
A
a
A
POINT A IN 4TH QUADRANT
POINT A IN 3RD QUADRANT
Convention Horizontal plane is always rotated
clockwise
4
PROJECTIONS OF A POINT IN THE 4 QUADRANTS
VP
VP
HP
P
P
PF
PT
HP
POINT IN 2nd QUADRANT
PT TOP VIEW PF FRONT VIEW
POINT IN 4th QUADRANT
POINT IN 3rd QUADRANT
PT
HP
HP
HP
VP
VP
HP
PT
PF
P
PF
P
VP
VP
5
How you will draw on the sheet
PF
PF
PT
y
y
x
x
PT
POINT IN 2nd QUADRANT
POINT IN 1st QUADRANT
PT
y
x
PT TOP VIEW PF FRONT VIEW
x
y
PT
PF
PF
POINT IN 4th QUADRANT
POINT IN 3rd QUADRANT
6
PROJECTIONS OF A POINT IN FIRST QUADRANT.
A
a
a
A
Y
a
a
a
X
a
A
Fv above xy, Tv below xy.
Fv above xy, Tv on xy.
Fv on xy, Tv below xy.
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Projection of lines, planes, solids

• Line consists of 2 points
• Plane consists of 3 or more points
• Solid consists of more than 3 points
• Therefore in order to project lines, planes and
  solids, we need to project their corresponding
  points and join them

8
AIM- TO DRAW ITS PROJECTIONS - FV TV.
INFORMATION REGARDING A LINE ITS LENGTH,
POSITION OF ITS ENDS WITH HP VP ITS
INCLINATIONS WITH HP VP
SIMPLE CASES OF THE LINE

1. A VERTICAL LINE ( LINE PERPENDICULAR TO HP //
   TO VP)
2. LINE PARALLEL TO BOTH HP VP.
3. LINE INCLINED TO HP PARALLEL TO VP.
4. LINE INCLINED TO VP PARALLEL TO HP.
5. LINE INCLINED TO BOTH HP VP.

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Orthographic Pattern
For Tv
1.
FV
A Line perpendicular to Hp // to Vp
For Fv
a b
TV
Orthographic Pattern
For Tv
2.
A Line // to Hp // to Vp
F.V.
For Fv
T.V.
10
True Length
3.
A Line inclined to Hp and parallel to
Vp (Pictorial presentation)
Orthographic Projections
4.
F.V.
A Line inclined to Vp and parallel to
Hp (Pictorial presentation)
Ø
T.V.
True Length
11
A Line inclined to both Hp and Vp (Pictorial
presentation)
5.
NOTE a and b are NOT the true angles
(inclinations) of the line with the planes
12
PROJECTIONS OF PLANES

• A plane is a two-dimensional geometrical entity
• It has length and width but no thickness
• For practical purposes, a flat face of an object
  may be treated as a plane
• A plane which has limited extent (has fixed
  shape) is termed as a lamina

• Information usually given
• Shape of the plane
• Inclination of its surface with one of the
  reference planes
• Inclination of one of its edges with the other
  reference plane will be given

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ONE SMALL SIDE INCLINED TO VP PICTORIAL
PRESENTATION
SURFACE INCLINED TO HP PICTORIAL PRESENTATION
SURFACE PARALLEL TO HP PICTORIAL PRESENTATION
FV-1
FV-2
FV-3
T V-1
T V-2
T V-3
ORTHOGRAPHIC FV- Apparent Shape TV-Previous Shape
ORTHOGRAPHIC TV-True Shape FV- Line // to xy
ORTHOGRAPHIC FV- Inclined to XY TV- Reduced Shape
14
Center lines

• Drawn to indicate the axis of cylindrical,
  conical or spherical objects or details.
• Thin long chains composed of alternately long and
  short dashes.
• Longer dashes are approximately 6 to 8 times the
  short dashes in length.
• Center of a circular curve is indicated by a
  cross
• made up of centerline chains.

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FOR T.V.
S.V.
F.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
L.H.SIDE VIEW
FOR F.V.
FOR S.V.
PICTORIAL PRESENTATION IS GIVEN DRAW THREE VIEWS
OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD
TOP VIEW
16
3rd. Angle projection
Top view
Front view
Right Side view
17
FOR T.V.
S.V.
F.V.
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
L.H.SIDE VIEW
FOR F.V.
FOR S.V.
TOP VIEW
PICTORIAL PRESENTATION IS GIVEN DRAW THREE VIEWS
OF THIS OBJECT BY FIRST ANGLE PROJECTION METHOD