Embodiments of the invention include methods and structures for controlling developer critical dimension (DCD) variations across a wafer surface. Aspects of the invention include an apparatus having developer tubing and an internal cam. The internal cam is coupled to a fixed axis. A flexible divider is positioned between the developer tubing and the internal cam. The flexible divider is coupled to the internal cam such that rotation of the internal cam about the fixed axis is operable to change an inner diameter of the developer tubing.