Suspension design

Hello, I am an engineering student and I'd like to have some advice on my issue.

 I am currently reproducing an existent suspension to measure roll center height and other characteristics depending on suspension travel but i have an issue : to create the roll center point i need to create a line from the contact point with the ground (wheel on the left) to the intersection of the control arms (to the right) but when I do that there is too much constraints and the suspension can't move anymore. How could I create this line and have it moving (following the intersection points) without impacting the suspension movement ?

I'm not if I'm writing in the right community so please do not hesitate to correct me.

Thanks

Raphaël COSTE

 

Edu 3DEXPERIENCE CATIA