So, I figured out how to do gears in Fusion 360 and I made a prototype of a new mechanism to transfer power from the stepper motor to the axle and combined it with the mount for the x axis rail.

I've still got a few more bits left to sort out, I have not made space in the green part for the ball bearing and I need to do some little tweaks here and there just to make everything look and work nicely.

I'm not sure how well these gears will work, the teeth on them are rather chunky but on the other hand splattering pancake batter onto a hot iron plate isn't something that should require that much accuracy, I bet I'll have to do a reprint as always...