The purpose of this work is to develop a mechatronics-oriented constrained model predictive control (MPC) based on the disturbance observer (DOB) that can address constraints on the actual control effort (i.e., the MPC output minus estimated disturbance). To this end, a novel approach using time-varying input constraints on the MPC controller output is brought into design. The proposed design is experimentally shown to be more effective than the standard MPC scheme and a scheme based on the MPC using the DOB without time-varying constraints.