Problem 2.5 Loci of Points

Problem 2.5 A circular disc of diameter 100 mm rotates about its center O for one revolution, during the rotation a point M which is at the point of the periphery of the disc moves to the center in a straight path when the disc completes the half revolution and then reaches back to its initial position in remaining half revolution of the disc. Draw the locus of the point M by assuming that the rotation of the disc and the motion of the point M are constant.

Loci of Points Problems - Engineering Drawing
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Draw a horizontal axis of the length equal to 100 mm. And mark the center point O on it.


Draw a vertical axis of the same length bisecting and perpendicular to the horizontal axis, passing through the point O.


With O as center and radius equal to 50 mm draw a circle.


Divide these circles into 8 equal divisions. And give the notations P0-Q0, P1-Q1, P2-Q2 etc., as shown into the figure.

Note:-You can give notations in any direction either in clockwise or anticlockwise.


Now divide the horizontal axis equally into same no. of divisions as of the circle, which are 8.


With O as center and radius equal to O1 on the horizontal axis draw an arc up to the respective divisional line of the circle i.e.,P0-Q0, P1-Q1, P2-Q2 etc. as per the figure given above. Like in the same way draw all arcs. And give the notations as M0, M1, M2 etc. as shown in the figure.


Draw a smooth medium dark free hand curve passing through the points M0, M1, M2 etc. as shown in the figure.This is the required answer.


Give the dimensions by any one method of dimensions and give the name of the components by leader lines wherever necessary.

Author: Vasim Machhar

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

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