The uncertainty on the identification of the inertial parameters of rigid bodies can be reduced by studying the motion for the identification experiments. This paper presents a method for measuring the center of mass and the inertia tensor of a rigid body by generating a complex 3D motion. The proposed method is intended to reduce the time consumed by the experiment and the post-processing of the data. This reduction on the time is achieved by using the same assembly for the center of mass and inertia tensor identification experiments as well as an algebraic method for the identification. The experimental setup consists on a Stewart Platform for the generation of the motion, a load cell and an inertial measuring unit. A study on the reduction of the uncertainty was developed. It was found that the uncertainty on the identification of the center of mass can be reduced with a static experiment that takes the object to different orientations, improving the numerical condition of the identification system. The uncertainty on the inertia tensor identification is reduced when the motion of the body is generated relative to different axes in space. The method was first tested on simulations to estimate the uncertainty and then validated experimentally.