This is for smaller ellipses than can be made with my other ellipsograph, it also has a larger range of ratios of major/minor axes. For a bigger one, you can scale it up, print it 100% infill and then just cancel the print, when it gets thick enough( 3mm seems to be plenty).

There are two versions, my first attempt, with gears made using simple arcs, and the second version, with "true" involute gears. Testing show that they both work fine.

Credit to user "ElicaTeam" on Youtube for inspiring this.

I just added 3 more ellipsographs that make a set that should nest together nicely for storage.

(Note: The nesting ellipsographs don't have any tolerances for printing, so they don't work as well as the first two that I posted.)