A rotational indicator comprises a mechanical reducer having a reduction factor that is variable without exchanging components. A plurality of identical double gears rotate about a pair of parallel fixed shafts, a large gear of each double gear being intermeshed with a small gear of a preceding double gear on the opposing shaft. An axially moveable pinion gear is rotationally fixed to a rotatable pinion shaft, and is engageable with any of the large gears of the double gears according to its axial location, whereby a reduction factor between a rotational input and the pinion gear is variable. The pinion shaft is coupled to an indicating mechanism, which can be a pointer of a dial assembly and/or a rotary electrical component. The rotational input can be bounded, and the reduction factor can be adjusted to provide a bounded output range that is compatible with the indicating mechanism.