A technique for implementing dynamic S curve stepper motor velocity profiles provides improved performance in controlling the motion of a mass. A method for controlling a moving mass comprises accelerating the moving mass according to a velocity profile, detecting that the moving mass has a specified position, and altering the velocity profile based on the detection of the moving mass having the specified position. The velocity profile is altered by reducing a maximum velocity of the moving mass, if the moving mass has the specified position before a maximum velocity of the velocity profile is achieved.