Understanding these constructions:
Probably the best way to understand the following constructions is to imagine the exact opposite to what actually happens. As we all know in the case of cam and follower systems the cam rotates imparting a displacement on the follower. When constructing these systems it is imagined that the cam remains fixed and the follower is drawn in different positions around the cam, in effect the follower is imagined to travel around the cam.
Important note before considering the constructions:
The minimum cam radius is the smallest radius of the cam, the maximum follower displacement is the maximum distance travelled by the follower and the radius maximum follower displacement circle is equal to the minimum cam radius + the maximum follower displacement.
|Step 1||Given the cam profile and the centre of revolution, draw the minimum cam radius circle and the maximum follower displacement circle with the axis of revolution as centre. The minimum cam radius and the maximum follower displacement are given in the question.|
|Step 2||Divide the circles in 30� divisions and project the intersections between these division and the cam profile onto the displacement diagram to intersect the corresponding angular displacement.|
|Step 3||Join all the points of intersection on the displacement diagram between the projections form the cam profile and the angular displacements.|