A technique for implementing dynamic S curve stepper motor velocity profiles provides improved performance in controlling the motion of a mass. The point of the conical piston is in physical contact with the discharge channel leading from the center of the inletdischarge port assembly to the discharge ports on the exterior of the inletdischarge port assembly. The laminations are selectively placed on the ferromagnetic body with the magnetic layer adjacent to the body such that the lamination is detachably attached to the body while the paint sample layer is displayed thereon.