18-05-2013, 12:00 PM
Projection of Points and Projection of Lines
Projection of PointS.pdf (Size: 2.27 MB / Downloads: 686)
Convention
• Top views are represented by only small letters eg. a.
• Their front views are conventionally represented by
small letters with dashes eg. a
• Profile or side views are represented by small letters
with double dashes eg. a
Symbol of projection
The method of projection used should be indicated in the
space provided for the purpose in the title box of the
drawing sheet. The symbol recommended by BIS is to draw
the two sides of a frustum of a cone placed with its axis
horizontal.
Straight line
Locus of a point, which moves linearly the
shortest distance between any two given points.
Location of a line
The location of a line in projection quadrants is
described by specifying the distances of its end
points from the VP, HP and PP.
• Parallel to both the planes.
• Parallel to one plane and perpendicular to the
other.
• Parallel to one plane and inclined to the other.
• Inclined to both the planes.
Projection of a line
• Obtained by projecting its end points on
planes of projections and then connecting
the points of projections.
• The projected length and inclination of a
line, can be different compared to its true
length and inclination.