A positive feed tool may include a motor, a power supply operably coupled to the motor to power the motor, a gear head and a spindle. The gear head may be operably coupled to the motor to be operated responsive to powering of the motor. The gear head may include a drive assembly and a feed assembly. The spindle may be operably 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 may include a feed rate oscillator having a spindle feed gear operably coupled to a differential feed gear. The spindle feed gear is operably coupled to rotate the spindle to selectively axially feed the spindle. The differential feed gear is selectively operably coupled to an input shaft turned by the motor. At least one of the spindle feed gear or the differential feed gear has a variable pitch diameter.