A steering system includes a differential transmission having an input shaft and an output shaft, a rotary input device attached to the input shaft, a movable steering effector in operable communication with the output shaft, an angular-to-linear converter which converts a rotative motion of the output shaft to a linear motion that acts to move the steering effector. Ioniser blades with sawtooth spikes create a corona discharge when charged to a high voltage, so that gas-borne particles are charged when passing through the corona area. Each rail post has on either side one channel of stepped cross section guiding vertically two or more shoring panels. The printing system is particularly adapted for use with substrates that are intended to be viewed when backlit, that is in conjunction with backlighting. The belt makes contact with the solid dosage form.