A motion enhancing mechanism assembly suited for use with fluid control devices such as a piezoelectric modulating actuator of a proportional control valve. Range-limited axial motion of the actuator is transmitted through an amplifier disc to cause tilting of a control plate initially in sealing registration with an orifice ridge surrounding a fluid conduit aperture. Tilting of the control plate opens a wedge-like gap through which fluid may flow with larger conductance than is available with a planar gap of uniform height otherwise achievable with the range-limited motion of the actuator.