A power tool includes a shaft rotatable about an axis and configured to drive a tool element, a motor armature, a first field coil, and a second field coil. First and second symmetrical stack parts each include a pole piece that is configured to receive respective first and second field coils. The first field coil is coupled to the pole piece of the first stack part such that portions of the first field coil extend past pole tips of the first stack part, and the second field coil is coupled to the pole piece of the second stack part such that portions of the second field coil extend past pole tips of the second stack part. The first stack part is coupled to the second stack part such that the first stack part and the second stack part together define an aperture that surrounds the shaft axis.