In those mechanisms, a high-torque, low backlash gearbox might be just the thing, and a 3D printable split planetary ... printed, except for a few screws. That it mates perfectly with a NEMA 17 ...

3D-printed gearboxes are always ... [ZeroBacklash] created a little strain wave gearbox (harmonic drive) for when you want to trade speed for torque on NEMA 17 stepper motors.