Does anyone know of an idler that can be mounted like a stepper motor? I was thinking about the idea that was mentioned where the z axis is moved by a single motor plus belt. If one of the z stepper motors were replaced with a free running bearing (probably not the right words), then the other motor could drive both a leadscrew and a gear connected to a belt connected to the other leadscrew. The belt could be routed above or below the lower platform.
No not seen any thing like it, design and print it But why? I think some the reasons why 2 steppers are use are, - It works - It's most likely cheaper 1 stepper + coppler vs belt, min 2 pullies, ball bearing + 1 longer spindel or your custom idler. - It's just simpler mechanics, no additional belt tightening I would go sofar an say 2x y-Motors may be Better