The print head carriage for a printer has end-mounted toothed clutches secured thereto and engageable with mating toothed clutches mounted on the carriage support shaft for rotation thereof upon near end of travel of the carriage across the printer. The teeth of the carriage mounted clutches are one-half pitch length out of phase with the teeth of the mating clutches so that, at each end of carriage travel, the mating clutches are caused to be incrementally rotated to thereby rotate the carriage support shaft and the record media drive shaft for advancing the record media a predetermined distance.