The study investigates the sedimentation dynamics of a rigid U-shaped disk in a viscous fluid, where inertia is negligible. Unlike planar disks that settle in a fixed orientation, U-shaped disks exhibit periodic pitching and rolling motions, leading to complex sedimentation trajectories ranging from quasi-periodic spirals to helices. The handedness of these chiral paths is determined by the initial orientation rather than the disk's geometry. The research provides a framework to interpret the motion of sedimenting particles of arbitrary shape, highlighting that even achiral particles can sediment along chiral trajectories. The study combines experimental observations and theoretical modeling to demonstrate the periodic reorientation dynamics and the resulting complex sedimentation patterns. The findings offer insights into the behavior of microscale materials and have implications for processes such as graphene segregation, microalgae harvesting, and microplastic separation.The study investigates the sedimentation dynamics of a rigid U-shaped disk in a viscous fluid, where inertia is negligible. Unlike planar disks that settle in a fixed orientation, U-shaped disks exhibit periodic pitching and rolling motions, leading to complex sedimentation trajectories ranging from quasi-periodic spirals to helices. The handedness of these chiral paths is determined by the initial orientation rather than the disk's geometry. The research provides a framework to interpret the motion of sedimenting particles of arbitrary shape, highlighting that even achiral particles can sediment along chiral trajectories. The study combines experimental observations and theoretical modeling to demonstrate the periodic reorientation dynamics and the resulting complex sedimentation patterns. The findings offer insights into the behavior of microscale materials and have implications for processes such as graphene segregation, microalgae harvesting, and microplastic separation.