A rotational actuator assembly employs a first torsion actuator having a shape memory alloy (SMA) tube with a first trained twist direction and a second torsion actuator having a SMA tube with an opposite trained twist direction collinear with the first torsion actuator with abutting proximal ends. A central fitting joins the proximal ends. A control system for temperature control of the first torsion actuator and second torsion actuator about an average temperature provides combined antagonistic rotation of the central fitting.