Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (d): Projections of Planes
So far we have seen the projections of points and straights lines.
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (c): Projections of Straight Lines
1. A line AB, 70 mm long is parallel to both HP and VP. The point A is 25 mm above HP and point B is 40 mm infront of VP. Draw its projections.
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (c): Projections of Straight Lines
When the line is parallel to both the planes then the projections are parallel to XY, since the line does not meet both HP and VP, it has no H.T and V.T.
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (c): Projections of Straight Lines
The point of intersection of line with a plane is called its trace.
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (c): Projections of Straight Lines
In all those previous examples of straight lines inclined to both the planes, sum of true inclinations was less than 90°
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (c): Projections of Straight Lines
A line may be positioned in infinite number of positions in Dehedral angles (ie, with respect to the vertical and horizontal reference planes).
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (c): Projections of Straight Lines
Orthographic projections of points with various positions in Dihedral angles are given in the last chapter.
Projections of Points | Engineering Graphics
Subject and UNIT: Engineering Graphics: Unit II (b): Projections of Points
1) A point M is 40 mm above HP and 30 mm infront of VP. Draw the orthographic projections.
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (b): Projections of Points
Consider a point A situated in First Quadrant, x units, in front of VP, y units above HP amd z units in front of PP as shown in Fig. 11.5.
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (b): Projections of Points
The Vertical plane VP and the horizontal plane HP are transparent and assumed to be infinitive in size.
Projections of Points | Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (b): Projections of Points
Though first angle and third angle projections are generally drawn in orthographic projections
Engineering Graphics (EG)
Subject and UNIT: Engineering Graphics: Unit II (b): Projections of Points
The point may be situated in any one of these four quadrants (or) may lie in the principal planes.