To improve the accuracy of manufactured mechanical parts, the geometric errors of a machine-tool should be evaluated and compensated in order to better master the deviations between the actual and nominal tool positioning (volumetric accuracy). Thus, a novel Multi-Feature Bar (MFB) for machine-tool geometric errors' identification was designed and manufactured. The MFB standard is made of Invar material. The proposed design of the MFB allows extracting three intrinsic parameters: one linear positioning and two straightness errors. The calibration of the MFB was performed on an accurate coordinate measuring machine (CMM) when applying the reversal technique, in order to separate the MFB's error forms from the motion errors of the CMM's mechanical guiding systems. Furthermore, an intercomparison was conducted between four National Metrology Institutes (LNE, PTB, CMI, UM) to evaluate the reliability of the proposed calibration methodology. Findings resulting from this intercomparison reveal dimensional stability of the MFB standard for geometric errors identification on CMM and machine-tool. Therefore, the use on machine-tool of the calibrated MFB, regardless of the harsh environment, guarantees its metrology traceability to the SI metre definition of few micrometres (<5 μm).
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