elongated thin strip stock is blanked to form interlocking laminas for electric motor or generator rotors or stators at successive blanking stations . at a final assembly station the laminas are stacked and pressed into interlocking relationship . in response to an operator input a predetermined number of reversals , or half turns about the stack axis of the previously stacked lamina are provided in order to compensate for nonuniform strip thickness to obtain a rotor or stator of substantially uniform height . alternatively the thickness of the strip stock is gauged at transversely spaced points on the strip to determine cross feed thickness variation in the strip whereupon the stacked laminas are automatically provided with a number of reversals about the stack axis in response to a thickness differential that would result in a parallelism error in the stack that exceeds a predetermined amount . rotor conductor slots are formed in the stacked laminas and are skewed to the stack axis by providing arcuate indexing of each lamina relative to the next preceding lamina in the stack by an arcuate increment that is automatically determined in response to operator entered inputs relative to the stack height , the skew angle , nominal lamina thickness and skew direction .