Abstract: A method and system are invented for adaptively and automatically retuning a closed-loop servo motor that is operating within normal limits. A first active set of configurable tuning constants is assigned to the servo motor, and motor performance is periodically measured to determine if performance is outside a retuning threshold, in which case the active set of configurable tuning constants is replaced by selecting a replacement set of tuning constants from a finite group of discrete predesigned sets of tuning constants. Actual performance of the servo motor is remeasured, and this process is repeated if the performance remains outside the retuning threshold. The predesigned sets of tuning constants are derived and stored in the servo motor software, typically as a result of pretesting the servo motor model by the manufacturer, for example using manual retuning.