Axial flux electrical motor assembly and methods of assembling the same

A method of assembling an electric motor includes coupling a rotor hub to a rotor disk to form a rotor assembly and slidably coupling the rotor hub to a shaft at a first position. The method also includes coupling a stator assembly to the shaft to define a first axial gap between the stator assembly and the rotor assembly. The method further includes sliding the rotor assembly to a second position along the shaft to define a second axial gap between the stator assembly and the rotor assembly. The second position is based on a measured back EMF constant of the electric motor when the rotor assembly is in the second position.