The design of beatup mechanisms (four link, six link, and conjugate cam) affects loom performance significantly. Researchers used computer aided design and analysis tools, including the Working Model software program, to analyze four link mechanisms, conduct a parametric study exploring the effect of geometry on lay motion, build models for six link mechanisms to identify geometric configurations leading to a long insertion period, and compare the motion of the lay for different beatup mechanisms. The acceleration of the cam driven lay was much higher than that of the link driven lay. The computer tools were effective for improving the operation, noise and vibration levels, and speed of the beatup mechanisms. By adjusting certain geometric parameters in the computer model, researchers refined the mechanisms to extend the filling insertion period. Further reduction of mass inertia for the lay mechanisms will produce even higher loom speeds. 3 refs.