Dolphin guides from Pacific Bearing Co., Rockford, Ill., simplify linear motion with only a rail and carriage. Standard carriages with cut-to-length rails let the user drive the one-piece carriage with a lead-screw, ball screw, or other mechanism. A standard-length Dolphin Guide assembly can be used with a leadscrew supported at both ends. Motor-mount or hand-crank attachments are available.