A new robust adaptive control scheme is proposed for the simultaneous force/motion control of constrained rigid robots including motor dynamics. When slow motor dynamics are present, two problems arise. First, the performance of the controller will be degraded because of the interaction between robot and motor. Second, the uncertainties in the robot are no longer in the range space of control, which means that conventional methods cannot be easily applied. To confront these problems, a novel sliding mode technique is proposed which can achieve robustness to parameter variations in both manipulator and motor. Also the joint position errors can be driven to zero and the force errors can be reduced to arbitrarily small values. No joint acceleration measurement is needed.