will this 4th axis work

[johnsattuk]

Not just the fine pitch but also the fact that they are flexible to mesh and I am not totally sure about the inner workings, but I think they have one more tooth than the gears they mesh with, or vice versa. Incredible concept and I guess very difficult to machine such precision.

Edward

Need 2 teeth difference and because of the fine pitch, need a bit of care when reasemmbling as it is easy to be one tooth out, do not force.