A trim router heat sink (100) with a bearing seat (136) and shaft lock (160) that mount to a trim router to act as a heat sink. A shaft (150) extends through the bearing seat and has a shaft lock (160). The shaft is held on one end by the trim router's motor shaft (118) and on the other end by a bearing (140). The shaft is connected to a collet (172) so that when the motor (110) of the trim outer is operated, the shaft turns the collet. The shaft (150) can be locked to facilitate the installation or removal of a cutting tool in the collet.