[Recage]

Dear community,
I am trying to model a valve in X-Flow. It consists of two parts moving along the x-axis. The parts are connected with a spring. Hence, the spring force is dependent on the distance between the two parts. This is where the problem comes in: how do I specify the spring force as a function of the distance between two parts?

In contrast it is very simple to specify the spring force for a single part as a function of its displacement: F = k * px
(k is the stiffness of the sping, px is the displacement of the current body).
Is there a way to consider the distance between two parts for the spring force?

Best regards,
Recage