Abstract: A trim router heat sink with a bearing seat and shaft lock that mount to a trim router to act as a heat sink. A shaft extends through the bearing seat and has a shaft lock. The shaft is held on one end by the trim router's motor shaft and on the other end by a bearing. The shaft is connected to a collet so that when the motor of the trim router is operated, the shaft turns the collet. The shaft can be locked to facilitate the installation or removal of a cutting tool in the collet.