Abstract: A power tool includes a housing that encloses a motor, and a collet configured to be driven to rotate by the motor. The collet defines a drill axis about which the collet is configured to rotate. The power tool also includes a sensor assembly having a front wall with a wall contact surface. The front wall includes a first wall portion and a second wall portion that define a gap therebetween. An object sensor is secured to the front wall proximate the gap. A support member includes a first end portion attached to the front wall and a second end portion attached to the housing. The support member extends from the housing to position the front wall forwardly of the collet such that the drill axis intersects the gap.