Draw the labelled displacement, velocity and acceleration diagrams for a follower when it moves with simple harmonic motion.

Roller follower is preferred over knife edge follower  Knife-edge of the follower will cause the wear of the cam.  Higher load on the small contact area the follower likely to cause wear at the tip of Knifeedge due to more stresses.  Knife-edge follower practically not feasible for higher torque / load applications.  More friction due to sliding motion of the knife-edge follower and hence, more maintenance.  Roller follower on the other hand produces smooth operation with less wear and tear of both cam and follower.  Pure rotational motion of roller follower causes less friction and less loss of power.  Considerable side thrust exists between knife-edge follower and the guide.