A spring mechanism for an electromagnetic drive unit converts or translates the movement and/or actuation of the electromagnet into a desired movement of the workpiece and enables simple and efficient tuning of the workpiece movement. The spring mechanism includes a housing, a spring connected to the housing, wherein at least two sections of the spring are movable with respect to the housing, a drive shaft that includes a first end having a magnet and a second end for attachment to a workpiece, and at least two tuning elements connecting the drive shaft to the movable portion of the spring. At least one of the tuning elements is adjustable. In one embodiment, the spring may be a flat spring, and the movable sections may each be positioned between a pair of cutouts defined in the spring.