This is a rack and pinion style linear actuator.
Due to the inclusion of a worm gear drive, the rack will maintain its position without the requirement to "hold" the gears static with a motor.
This requirement was necessary in the application it was intended (solar panel alignment drive)
This was designed in a combination of OpenSCAD and Blender.
The motor used is an RS-540. It could be driven with a smaller motor.
The motor is coupled to the worm gear via friction-fit. Some drilling my be required for the deliberately undersized hole for the motor shaft to couple with.
Currently printed in PETG (Urban Grey) with a .6mm nozzle.
Only one piece requires support which is the "cover".
This model uses the slider component from the RepRap Snappy for the rack alignment (https://reprap.org/wiki/Snappy attrib: RevarBat).
The author hasn't provided the model origin yet.