sicssor hinge

hi,

I`m trying to get a sicssor hinge to work inside grasshopper. The endgoal move the tip of the hinge along a curve and to generate the shape of two cams which are connected to the back of the hinge. I started of with "gears" in kangaroo, but I the upper arms are not rotating around one axis/point. The current try uses rigid body and kangaroo_2, but it seems, that the arms of the hinge are "glued" together and the meachnic is not working.

any advice?

thanks konrad

ps: also the simulation fails when all verts are anchored in z.