I have an assembly with a helix inside that is mimicking a rope. I have added an equation in the assembly that changes the number of revolutions to simulate the rope winding and unwinding. I do this by referencing the equation to a part that I can stretch and shorten which in turn changes the helix. My problem is that I have to rebuild my assembly twice for the equation to work. The first rebuild is to change the length of the part and the second for the equation to work. Is there a way for all of this do be done in the same step? I am also trying to animate this motion but I cannot get the rope winding and unwinding to animate and I think having to rebuild twice is the reason. Any help would be appreciated.