A rotor and an electrical machine for a motor vehicle drivetrain. Interactive print jobs are print jobs that are automatically stored in the printer memory and not printed unless they are explicitly activated by a user. During the brazing cycle, the brazing paste flows into and fills the at least one crack and thus repairs the metal workpiece. The method provided by the present invention has high security, simple operation, stable quality of product, and is suitable for continuously produce on a large scale. The training system stores a score based in part on a comparison of the trainee’s response with an answer stored in training system memory.