Follower displacement

The position of the follower from a specific zero or rest position (usually it’s the position when the follower contacts with the base circle of the cam) in relation to time or the rotary angle of the cam is the follower displacement.

Pressure angle:

The angle at any point between the normal to the pitch curve and the instantaneous direction of the follower motion is called pressure angle. This angle is important in cam design because it represents the steepness of the cam profile.