Free Vibration Analysis of Gantry Type Coordinate Measuring Machines

Coordinate Measuring Machines (CMMs) are designed for precision inspection of complex industrial products. Even though CMMs have high accuracy in electrical systems, mechanical structures prevent very high accuracy in these machines. Mechanical accuracy of CMMs depends on both static and dynamic sources of error. In automated CMMs, one of the dynamic error sources is the vibration of probes, due to inertia forces resulting from parts deceleration. Modeling of a gantry type CMM, based on the Timoshenko beam theory, is developed and the natural frequencies of the CMM system, at different positions of the probe, are calculated. Findings from the analytical and finite elements method indicate high accuracy and good agreement between the results.