Question

A cam should be designed only using uniform rise and fall within half of the cam, the remaining is dwell period, and without any dwell period in between the rise -fall periods and rise and fall periods should be same. The maximum rise in follower is 30 mm. How much the follower will rise when the follower is 120 degrees from its initial position of a cam?

(a) 30

(b) 20

(c) 15

(d) 10

I have been asked this question during a job interview.

This intriguing question comes from Cam in division Curves used in Engineering Practice of Engineering Drawing

Answer 1

The correct answer is (d) 10

For explanation I would say: According to the given conditions there is only movement in follower up to 180 degrees of shaft rotation and between it at the middle the follower make maximum rise that is at 90 degrees. 120 – 90 = 30 degrees. For 90 degrees it is 30 mm so for 30 degrees it will be 10 mm when the follower is 120 degrees from its initial position of cam.