Newark element14 Hollow-shaft stepper motor
While conventional hybrid stepper motors use a permanent magnet in the rotor, Lin Engineering's patented design uses a ring magnet in the stator instead. This helps to reduce the detent torque (unenergized drag torque) because the magnetic flux path can reach over the stator windings and go through only the outer edge of the rotor. Reducing detent torque improves accuracy, smooths operation and reduces noise. Modifying the magnet location does not change the dynamic torque. Additional features include a large hollow-shaft design and high step accuracy.