What is 1st angle?
1. First Angle Projection : In the first angle projection, the object is placed in the 1st quadrant. The object is positioned at the front of a vertical plane and top of the horizontal plane. First angle projection is widely used in India and European countries.
Why do we use 1st and 3rd angle projection?
We consider that horizontal plane rotates in clockwise direction after having projection on it. that’s why we use 1st angle and 3rd angle projection. because only in this two quadrants we will get the both views after clockwise rotation of horizontal plane.
How do you read 1st and 3rd angle drawings?
The difference between first and third angle projection is in the position of the plan, front and side views. In third angle, what you see from the right would be drawn on the right. In first angle, the view from the right would be projected through and drawn on the left.
What is 2nd angle projection?
In Second quadrant, Vertical plane (VP) lies in between object and observer. Therefore front view of the object will lie on vertical plane whereas top view will lie on horizontal plane. As per rule of projection when horizontal plane is rotated 90 degree in clockwise direction, top and front view will overlap.
What is 1st angle and 3rd angle?
To get the first angle projection, the object is placed in the first quadrant meaning it’s placed between the plane of projection and the observer. For the third angle projection, the object is placed below and behind the viewing planes meaning the plane of projection is between the observer and the object.
What is the difference between 1st angle and 3rd angle?
What is first angle and 3rd angle?
What is the difference between 1st and 3rd angle?
Why 2nd and 4th angle is not used?
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 the difference between first and third angle projection?
To get first angle projection object is place in between the plane of projection and observer and for the third angle projection plane of projection is placed between the object and observer. State of Projection Plane. In first angle of projection plane of projection is taken solid while in third angle of projection it is taken as transparent.
What is first and third angle projection?
Both first angle and third angle projection are the two ways of drawing in orthographic that usually consists of three different views of an object in two dimensions. They are used to obtain engineering drawings for clarity.
What is a third angle?
Definition of third angle. : an angle of the Great Triangle formed on the palm by the intersection of the lines of Head and Mercury that when clear, well-pointed, and even is usually held by palmists to indicate quickness of intellect, individuality, and good health. — called also middle angle. — compare first angle, second angle.
What is third angle view?
In third angle projection, the observer is on the right side of the object and the orthographic view is projected on a plane located between the view point and the object. The right view is projected onto the right side of the front view and the top view is projected above the front view.