The present disclosure includes a method of assembling a plurality of rotor cores for an electric converter. The method includes providing a core robotic system employing force control feedback and an insert assembly robotic (IAR) system; placing a rotor core of the plurality of rotor cores on a mandrel by the core robotic system employing force control feedback, wherein each rotor core from the plurality of rotor cores includes a plurality of cavities; and placing a plurality of magnetizable inserts into the plurality of cavities in the rotor core by the insert assembly robotic (IAR) system employing force control feedback.