I am trying to get a spring to move and I have set a distance mate in the model and then I have changed the distance mate  in "edit dim" in the assembly mate in the motion study. I see no "spring action" as I wish to see. I do realize that mates within the animation -motion study are independent of the assembly model mates. This seems like it should be a simple thing to do. ANY suggestions would be helpful. Am I approaching this from the wrong angle?