Abstract—Monitoring of production systems with special attention to the manufacturing processes is subject of intensive research efforts. Besides additional sensors close to the contact point between tool and workpiece, the pre-installed drive internal measuring systems of the feed axes offer a potential opportunity to access these forces. Due to their distance from the point of action, superimposed phenomena must be taken into account to achieve an appropriate estimation. In the case of linear feed axes, this applies in particular to prevailing frictional torques and forces. Depending on the structure of the feed axis, position- or workspace-dependent effects should also be considered. In addition, the influence of gravity becomes noticeable for vertical axes. In the context of this paper, suitable models and identification routines for both phenomena are developed and validated on a three-axis machine tool. Particular attention is devoted to an automated parameter identification as well as a compromise between model accuracy and the number of assignable parameters. Finally, all models are verified via exemplary air cutting and face milling experiments.