End play control construction to regulate the end play of a shaft of an electric motor between an end bearing and the rotor secured to said shaft, which comprises a bushing secured to the shaft adjacent the rotor and having an annular outwardly facing slot, a thrust collar slip fitted on the shaft and having an annular projection axially aligned with the slot in the bushing and disposed in final position in mashed engagement with the bushing by an ultrasonic horn under controlled conditions with an ultrasonic weld joining the bushing and thrust collar together to thereby space the assembled bushing and collar from the bearing of the order of 0.003 to 0.018 inches to establish a minimal amount of end play of the shaft. In a second embodiment of the invention the annular slot is in the thrust collar and is disposed in axial alignment with the annular projection in the bushing.