Embodiments of the present invention relate to a linear actuator in which the play and backlash in the linear motion of a stepper motor is reduced through the use of a torsion spring coupled to the stepper motor splined shaft. Also, embodiments of the invention include a controller designed for holding in the hand or mounting to a table with a bi-directional self-zeroing control knob which controls actuator speed and displacement. A flash memory unit may be included in some embodiments in order to save position information and other information about the linear actuator when power to the linear actuator is stopped.