Within this paper, a model based deflection compensation for a mobile machine tool prototype is presented. The model compensates the deflection of the tool center point (TCP) based on strain gauge measurements at the machines foot modules. The measured strains at each foot are used to calculate pose dependent gravitational forces as well as disturbance forces. These forces are then passed to the model. Hence, the model reconstructs the deflection of the TCP based on the measured forces at the foot modules