Superconducting technology offers the prospect of sharply increase the power density of rotating electrical machines, especially in the low speed, high torque range, with impact in applications such as wind energy and aircraft propulsion. Among the enabling technologies, stacks consisting of piling up layers of high temperature superconductor may provide a source of magnetic flux density for torque production, without the complexity of superconducting wound rotor poles. For this to happen, careful designs, optimizing electromagnetic, mechanical and thermal aspects at the same time, must be developed. In that sense, this work applies a recently developed combined electromagnetic formulation to compute the magnetization level of high temperature superconductor stacks installed in the airgap of an electrical motor after field cooling magnetization. The results are congruent with the applied field, show a strong interaction between teeth and stacks and provide a way of initializing the state of the machine prior to operation.