# Problem 6.7 Projection of Solids

Problem 6.7 Projection of Solids – A cone of diameter of base 60 mm and axis length equal to 100 mm rests on a point of its periphery of the base on H.P. such that its axis is inclined at an angle of 35° with the H.P. and 60° with the V.P. and the apex is near to the observer. Draw its projection.

## Procedure:

Step-1 Draw a horizontal x-y line of some suitable length.

Step-2 Draw a circle of diameter 60 mm, below the x-y line at some suitable distance, and divide this circle into 12 equal divisions, as shown into the figure. And give the notations. It is the top view of the 1st stage.

Step-3 From the center of the circle in top view, draw a perpendicular vertical projector of the length equal to 100 mm from x-y line, and give the notations as shown into the figure. And from the notations of the circle in top view, draw perpendicular vertical projectors up to the x-y line. From these end points draw slant lines connecting to the apex point  “ o’ ”  in the front view, and give the notations as shown into the figure. It is the front view of the 1st stage.

Step-4 Now copy the front view of the 1st stage as the front view of the 2nd stage with the same dimensions, such that the center line of the rectangle should be inclined at an angle 35° with the x-y line, and the corner of the rectangle that is point e’ should touch with the x-y line, as shown into the figure. And give the notations. It is the front view of the 2nd stage.

Step-5 From the notations of the front view of the 2nd stage draw vertical projectors into down ward direction and from the top view of the 1st stage draw projectors into horizontal direction as shown into the figure, which will intersect with each other at respective points.

Step-6 Now connects these all the points with either straight lines or curves in sequence, depending on the shape of the cone, as shown into the figure. It is the shape like a cone. But be careful that some of these lines or curves are dotted because of hidden. And give the notations. It is the top view of the 2nd stage.

Step-7 Copy the top view of the 2nd stage as the top view of the 3rd stage, at an angle 60° with the x-y line such that the center line should be inclined at the angle 60°,  as show into the figure with the same dimensions. And apex of the cone which is point o in top view should be away from the line x-y. 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 Now connects these all the points with either straight lines or curves in sequence, depending on the shape of the cone, as shown into the figure. It is the shape like a cone. But be careful that some of these lines or curves are dotted because of hidden. 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.

## Author: Vasim Machhar

An Engineering Drawing Geek. Working at Noble Group of Institutions, Junagadh as Head of Mechanical Engineering Department.