Why we dont use 2nd and 4th angle in engineering drawing?
As per rule of projection when horizontal plane is rotated 90 degree in clockwise direction, top and front view will overlap. Overlapping projection views create confusion in the drawing. Therefore 2nd angle projection system is not used. Therefore fourth angle projection is also not used.
What is second angle projection in engineering drawing?
For 1st angle projection system, we place object in 1st quadrant, for 2nd angle projection system, we place object in 2nd quadrant and so on. In Second quadrant, Vertical plane (VP) lies in between object and observer. To sum up, because of overlapping of front and top views 2nd and 4th angle projections are not used.
Why 3rd angle projection is used?
In the third angle projection, the object is placed in the third quadrant. Third angle projection is widely used in the United States. The projection planes come between the object and observer. The plane of projection is taken as transparent in 3rd angle projection.
What is 3rd angle of projection?
3rd Angle project is where the 3D object is seen to be in the 3rd quadrant. It is positioned below and behind the viewing planes, the planes are transparent, and each view is pulled onto the plane closest to it. The front plane of projection is seen to be between the observer and the object.
What is symbol of Third Angle Projection?
The third angle symbol is shown in Figure 1. It is represented by the circular top view of the cone with the right view of the cone to the right of it. In the right-side view, the narrow end of the cone is pointed towards the top view.
What does the 3rd angle projection symbol mean?
The projection symbol used to represent third angle projection shows what you would see when looking at the cone from the left, drawn sitting to the left of the drawing of the front face of the cone. Third angle projection symbol. AS 1100 recommends the use of third angle projection.
What are the standard views used in a 3rd angle projection?
Third angle projection is one of the methods of orthographic projection used in technical drawing and normally comprises the three views (perspectives): front, top and side.
What is left side view?
3D views are named from the perspective of the viewer The Left view, is on the left of the object when you look at the front, from the outside of the object. Likewise, the back view is on the back of the object, as you look at the front of the object, from outside the object.
What do you call a view that is located at the left side and aligned with the front view?
Multiview orthographic projection – Wikipedia.
What does a hidden line look like?
A hidden line, also known as a hidden object line is a medium weight line, made of short dashes about 1/8” long with 1/16”gaps, to show edges, surfaces and corners which cannot be seen.
What is the other name for plan view?
In such views, the portion of the object above the plane is omitted to reveal what lies beyond. In the case of a floor plan, the roof and upper part of the walls may be left out. Basically, a plan view is just another name for the top view of a 3D object.