Nema 17 Rack and Pinion Actuator

I have been working on a humanoid animatronics project, and one of the hardest things for people in the industry to master, is a robotic mouth. Because of the flexible nature of lips and the mouth shape in general, it makes it extremely difficult to mimic the complexity of our continuous muscles that surround our mouth. This actuator is a modular component in what will eventually be my take on an animatronic mouth. This is a building block, and a simple one at that. This actuator will be used for a proof of concept, and the only functionality is to have a Nema 17 encoded, attached to a rack and pinion system. I could also have used a servo, but I am attracted to the resolution of the steppers for this project.