Abstract: A modular toy construction system is provided, comprising modular toy construction elements having either first connectors or second connectors, connectable to the first connectors. The system includes a worm drive element with an elongate body with a longitudinal axis and a length that is a discrete multiple of a fixed modular distance. A helical track is formed along the longitudinal axis of the elongate body. The system further includes a guide element with a body having a length, width, and longitudinal direction. A worm bearing is formed in the body of the guide element, and a track guide member is formed on a concave surface of the worm bearing. The track guide member is configured for cooperating with the helical track of the worm drive element. The helical track has a pitch of one turn for each four fixed modular distance of the length of the worm drive element.