Use the Cam command 
to apply a cam relationship between a closed loop of tangent faces on one part (A) and a single follower face on another part (B). The follower face can be a plane, a cylinder, a sphere, or a point.
When you select a planar face as the follower element, the planar face is considered to be infinite. In some cases, this may not give you the cam behavior you want.
If part geometry changes such that the closed loop of tangent faces becomes non-tangent, the relationship will fail.
A barrel cam is created when you select a chain of curves as input for the cam definition. The selected edges for the chain are merged into a composite curve for processing.
Shown below are the follower (A) and the curve chain (B).
Cam and follower input geometry is described below.
Chain of curves (Cam):
Open and closed curves
3D path containing arcs, B-spline curves and must be tangent continuous.
The chain of curves can be from an edge coming from a sketch, design body, construction curve or similar input.
Surface (Follower):
Cylinders
Torii
Spheres
You can use the Flip command if the cam is positioned opposite of the desired location.
Note:
Other relationships, such as axial align and mate, must be applied to maintain the desired orientation of the part containing the cam relationship during motor simulation.
Interference may exist at some positions and is ignored.