Method for fabricating an induction rotor

Method for fabricating a rotor for an induction motor, comprising:

• providing an induction rotor assembly comprising a rotor core having first and second ends, and a plurality of conductor bars disposed within grooves at an outer periphery of the rotor core, each conductor bar having a respective first exposed end extending beyond the first end of said rotor core, each first exposed end having a respective enclosed opening;
• casting a first flow of molten material to form a first shorting end ring only extending away from the first end of the rotor core in a direction axially outward from the rotor core, the first flow of molten material partially flowing in a direction axially inward from the first end and terminating to form an overcast that terminates adjacent to the first end in the direction axially inward from the first end, wherein the molten material flows between said first exposed ends and through said respective enclosed openings in forming the first shorting end ring, thereby creating a mechanical interlock between the first shorting end ring and the conductor bars;
• preheating the rotor assembly prior to the casting of the molten material to form the first shorting end ring;
• and
• machining the overcast to form the first shorting end ring only extending away from the first end of the rotor core in a direction axially outward from the rotor core.