Number of days in the simulation that it takes for the flux rope to form vs. the twist parameter (β). The solid lines denote the day of formation for flux ropes on both the external (stars) and internal (diamonds) PILs. The dashed lines denote the days on which these flux ropes begin to lift off. For the internal PIL the twist parameter denotes the twist of an individual bipole, while for the external PIL it is the combined twists of both bipoles.