I'm designing an inverted cable driven stewart platform and wondering if any one has experience modeling this sort of thing and analyzing it in SW?

My first pass was a 3D sketch with weldment profiles for the structure and cable.  It works well with simulation as far as I can get it to spit out axial forces (tension) in the cables, but it is very difficult to change cable lengths.  Even with a design table I easily wind up with kinematic inversions.  Also it is easily possible to show compression in the cables, which in reality would be impossible.