Determining the right Mechanism in creo

[CC_9824097]

Hello,

I have 2 parts as shown below, ive made the parts so that the top sits flush with the bottom part. I want to be able to pivot the top part slightly so Its angle changes only by a couple of degrees either side. I've tried to use the cylinder mechanism however because my shape is more of an oval than a sphere, a collision occurs when i pivot the top part.

Are there any other mechanisms that might work for this situation in order to pivot the top part without collisions? 

Thank you in advance!    

[Tdaugherty]

Have you tried using a pin constraint? That seems like it might be what you're after. You can limit the rotation to avoid collision.

[mvitárius]

If both of them are oval, and both are a different oval (the upper one having smaller major axis) so one can move on the other (Am I right so far?), you'll have to use application->mechanism->CAM connection. Then either you enable collision detection on your assembly (which may or may not work depending on your luck mostly), or you set and angle offset constraint.