Problem 5.9 Projection of Planes – A circular plate of diameter 80 mm is resting on a point of its periphery on H.P. such that it makes an angle of 40° to the H.P. And the diameter passing through the point of its resting on H.P. makes an angle of 60° with V.P. Draw the projections of it.
Step-1 Draw a horizontal x-y line of some suitable length.
Step-2 Draw a circle of radius 40 mm below the x-y line at some suitable distance. It is the plan of the 1st stage.
Step-3 Divide the circle into 8 equal divisions, and give the notations.
Step-4 From the notations given on the circle, draw vertical projectors up to the x-y line, through these projectors, draw a horizontal medium dark line on the line x-y & give the notations. It is the front view of the 1st stage.
Step-5 Copy the front view of the 1st stage at an angle 40° with x-y line such that the point a’ should be on the x-y line. And give the notations on it. This is front view of the 2nd stage.
Step-6 From the front view of the 2nd stage draw downward projectors and from the top view of the 1st stage draw horizontal projectors in right hand side direction as shown in the figure which will intersect with each other at respective points. Then give the notations on it and connects these all the points in sequence by a medium dark smooth free hand curve. It is top view of the 2nd stage.
Step-7 Copy the top view of the 2nd stage at an angle 60° with the x-y line such that the line c-g should make the angle, as show into the figure with the same dimensions. And give all the notations on it. It is the top view of the 3rd stage.
Step-8 From the front view of the 2nd stage, draw horizontal projectors, and from the top view of the 3rd stage draw vertical projectors in upward direction, which will intersect with the previously drawn projectors at respective points.
Step-9 From these respective points of intersections, draw a smooth medium dark free hand curve, and give the notations. It is the front view of the 3rd stage.
Step-10 Give the dimensions by any one method of dimensions and give the notations as shown into the figure.