  Improving the safety of collaborative manipulators necessitates the reduction
of inertia in the moving part. Within this paper, we introduce a novel approach
in the form of a passive 3D wire aligner, serving as a lightweight and
low-friction power transmission mechanism, thus achieving the desired low
inertia in the manipulator's operation. Through the utilization of this
innovation, the consolidation of hefty actuators onto the root link becomes
feasible, consequently enabling a supple drive characterized by minimal
friction. To demonstrate the efficacy of this device, we fabricate an
ultralight 7 degrees of freedom (DoF) manipulator named SAQIEL, boasting a mere
1.5 kg weight for its moving components. Notably, to mitigate friction within
SAQIEL's actuation system, we employ a distinctive mechanism that directly
winds wires using motors, obviating the need for traditional gear or belt-based
speed reduction mechanisms. Through a series of empirical trials, we
substantiate that SAQIEL adeptly strikes balance between lightweight design,
substantial payload capacity, elevated velocity, precision, and adaptability.
