Abstract: The disclosed mechanism includes multiple links having adjustable-length drive units connected in series and operated coordinately. The illustrative form of adjustable-length drive unit has oppositely extending elements oppositely threaded in a body that is secured to a mount, the oppositely extending elements being keyed to each other for conjoint rotation that allows extension and contraction of the drive unit. In one form, successive drive units of successive links produce tilting of articulated links in respective planes perpendicular to each other.