Abstract: The invention is a machine for balancing drive shafts under computer control. Compensatory weights are formed in a weight-forming dye assembly which is coaxially repositionable in relation to the longitudinal axis of the drive shaft. Additionally, the weights formed are transported along an axis parallel to the longitudinal axis of the drive shaft, and are secured to the drive shaft utilizing a welding head which is selectively positionable along one side of the length of the drive shaft. Sensors are provided to determine the out-of-balance of the shaft, and an associated computer performs the necessary calculations for determining the appropriate position and mass of the compensatory weight.