Accurate force and moment measurement in spring testing machines by an integrated hexapod-shaped multicomponent force transducer

In spring testing machines, measurement of transversal forces and bending/torsion moments, beside vertical force, is crucial for spring characterization. For this purpose, the more advanced industrial machines are typically equipped with multicomponent force transducers (MFTs), composed by different sensors each one dedicated to a single force component. However, such assembled MTFs present unsolved technical problems, i.e. moment measurements are not performed and the periodic calibration is hard to manage. To overcome these problems, a hexapod-shaped MFT was devised and integrated in a new model of industrial spring testing machine, thus enabling simple periodic calibrations and ensuring measurement traceability, besides measuring the moment components. The present work deals with the performance evaluation and metrological validation of the system.