Print in place design using a novel planetary gearbox which allows for solid sun and planet gears common to both stages with crazy gear ratios possible.
The default settings allow for a layer height of 0.2 which corresponds to the gap between the ring gears. Make sure this one-layer gap is preserved when slicing. Separate after printing with a sharp tool before attempting to turn the gears. An M8 nut, bolt and wrench might come in handy to "crack" the gears loose.