A positive feed tool includes a motor, a power supply coupled to the motor to power the motor, a gear head and a spindle. The gear head is coupled to the motor and operated responsive to powering of the motor. The gear head includes a drive assembly and a feed assembly. The spindle is coupled to the gear head to enable the spindle to be selectively driven rotationally and fed axially based on operation of the drive assembly and the feed assembly, respectively. The feed assembly includes a feed rate oscillator having a spindle feed gear coupled to a differential feed gear. The spindle feed gear is coupled to rotate the spindle to selectively axially feed the spindle. The differential feed gear is selectively coupled to an input shaft turned by the motor. The spindle feed gear or the differential feed gear has a variable pitch diameter.