a maintenance system for maintaining a scalable printhead array comprises : a pair of tracks disposed in parallel and on opposite sides of a printhead array ; a shaft extending between the tracks and configured to engage with each track to move along the tracks ; a plurality of maintenance modules mounted in series along the shaft between the tracks and configured to move along the tracks with the shaft to perform maintenance operations on a plurality of printheads of the printhead array , the tracks being configured to guide the shaft and the plurality of maintenance modules along a path from a resting position to an operating position the printhead array and from which at least one of the plurality of maintenance modules performs a maintenance operation on at least one printhead of the printhead array ; and an actuator configured to move the shaft along the tracks .