Unfortunately, long-throw linear actuators are a little harder to come by, so it’s nice to know you can 3D-print linear gearing ... The pinion fits a trimmed servo crank arm, the mating rack ...

Towards the bottom is a 3D printed auger. The auger is super glued to the gear of a servo. The 9g servo is small and comes with internal limiters that only allow it to rotate about 180 degrees.