CNC Machine Rigidity Mapping Template (Excel + MATLAB script)

Rigidity mapping is essential for diagnosing geometric and dynamic performance bottlenecks in CNC machines—especially high-precision and high-speed systems where compliance-induced errors (e.g., tool deflection, chatter, form deviation) directly impact part quality and process capability. The Excel component serves as a standardized input interface: it structures experimental test plans (e.g., grid-based probe locations), logs force–displacement measurements from sensors (LVDTs, strain gauges, or laser interferometers), applies unit conversions and calibration corrections, and exports cleaned time-series or steady-state data to MATLAB. The companion MATLAB script performs core computational tasks—including coordinate transformation, finite-difference-based stiffness matrix estimation (k = ΔF/Δδ), spatial interpolation (e.g., thin-plate splines or RBF), modal assurance criterion (MAC) validation against FEA predictions, and generation of color-mapped rigidity heatmaps (X-Y-Z stiffness components) and contour plots. Advanced versions integrate uncertainty propagation (via Monte Carlo sampling on sensor noise models) and correlate rigidity gradients with measured surface finish or dimensional error distributions across machined test parts—enabling closed-loop feedback for mechanical redesign (e.g., rib stiffening), fixture repositioning, or adaptive feedrate scheduling.