Yet another one of my experiments with gear designs (and I'm not done yet). Every gear has a different number of teeth, and the sun gear is not in the center (thus literally eccentric). Still, quite fidgetable.
The hex holes should fit normal hexagonal pencils.
Note: With a bit of force this model can be disassembled. Depending on printer, filament, settings and some luck, the force required varies, and for some the model even disassembled by itself. I'm sorry for that! If it happens, you can probably reassemble it (the ring can be squished a bit to get gears in or out) and thus have some kind of puzzle, but that is selling a bug as a feature…
However, if this model doesn't work for you I recommend the “binary sun gear”, it is more stable and also eccentric (and I find it more interesting).
I added another version ("tighter") with lower tolerances.
Printing: I recommend random seam placement.