Abstract: A flow control device for regulating fluid flow through a length of flexible tubing comprising (a) a body assembly comprising a lower surface with a groove for supporting a length of flexible tubing, opposing side walls extending in the vertical plane along the longitudinal axis from the lower surface defining a passage for the tubing, a guide groove in one of the side walls, a rack gear positioned in the guide groove; (b) a rotatable cam assembly comprising a cam with an irregular radius which, at one position of rotation, extends into the passage, a pinion gear extending axially from and having the same center of rotation as the cam, wherein the pinion gear extends into the guide groove and operatively engages the rack gear; and (c) a cover connected to the top of the body assembly for retaining the pinion gear in operative engagement with the rack gear.