Orthographic Projection
Orthographic projection is a agency of drawing an 3D object from dissimilar directions. Usually a front, side as well as innovation view are drawn as well as then that a individual looking at the drawing tin encounter all the important sides. Orthographic drawings are useful specially when a blueprint has been developed to a phase whereby it is close cause to manufacture.
There are two ways of drawing inwards orthographic - First Angle as well as Third Angle.
The master copy projection planes as well as quadrants used to practise drawings are shown inwards Figure 1. The object tin endure considered to endure inwards whatever of the four quadrants.
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Figure 1. The master copy projection planes as well as quadrants for creation of drawings. |
First Angle Projection
- In this the object is assumed to endure positioned inwards the first quadrant as well as is shown inwards figure 2.
- The object is assumed to endure positioned inwards betwixt the projection planes as well as the observer.
- The views are obtained past times projecting the images on the respective planes.
- Note that the correct manus side persuasion is projected on the bird placed at the left of the object. After projecting on to the respective planes, the bottom bird as well as the left bird is unfolded on to the front end persuasion plane.
- i.e the left plane is unfolded towards the left side to obtain the correct manus side persuasion on the left side of the front end persuasion as well as aligned alongside the front end view. The bottom plane is unfolded towards the bottom to obtain the run past times persuasion below the front end persuasion as well as aligned alongside the front end view.
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Figure 2. Illustrating the views obtained using offset angle projection technique. |
Third Angle Projection
- In the 3rd angle projection method, the object is assumed to endure inwards the third quadrant. i.e the object behind vertical bird as well as below the horizontal plane.
- In this projection technique, placing the object inwards the 3rd quadrant puts the projection bird betwixt the viewer & the object as well as is shown inwards figure 3.
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| Figure 3. Illustrating the views obtained using offset angle projection technique |
A summary of the departure betwixt 1st & 3rd angle projection is shown inwards Table 1.
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| Table 1 |