<p>This study presents a novel flexible rotational joint implemented in a planar mechanism to analyze the clearance effects on trajectory accuracy and torque transmission. The proposed joint eliminates common problems in mechanisms, such as those caused by assembly imperfections or manufacturing tolerances that conduct backlash in joints based on shaft-bearing that compromise the path accuracy in the mechanism. The innovative design features a flexible rotational joint with four leaf springs acting as cantilever beams, supported by two frames; this design enables a relative rotational motion between links attached to the joint through the leaf spring deformation. The design was evaluated using finite element analysis (FEA) to assess stress and deformation behavior. The flexible joint was integrated into a slider-crank mechanism to validate the concept, and its clearance was analyzed via image processing techniques using the OpenCV library. This approach enabled a comparative study of the trajectory accuracy of the mechanism to determine the impact of the flexible joint in contrast with a shaft-bearing joint. This research includes a dynamic analysis to compare the torque transmission using flexible and conventional joints. The findings of this investigation prove the improvement in the accuracy of the mechanism implementing the proposed flexible rotational joint. However, the results also indicate that mechanisms incorporating the flexible joint require higher input torque compared to those using conventional joints.</p>