Linear Actuator (Ball Screw)

Working on a new project requiring (12) ballscrew actuators prompted R&D'ing cost effective solution.This led to many months of developing a 3D printed ball screw with an encoder and hardware cost of 35$/each. Multiple configurations posted for different travel lengths.

Travel Configurations:
125-200mm
150-250mm
175-300mm
200-350mm

Specifications:
Designed around 0.125" (3.175mm) ball bearing
Screw Pitch Diameter: 12mm
Screw Pitch: 4.5mm
Actuation Speed: 23.1mm/s
Encoder: 62.66667P/mm
Gearmotor: No Load 560RPM, 0.5A (See attached observations)
Force: 105N @ 1.0A (assuming 75%e)
Force: 367N @ 2.4A (assuming 75%e)

I have not tested linear force simply because I don't have appropriate hardware to do so. At 1.5A, I am unable (or unwilling) to stop the actuator by hand in compression. Further testing will happen as I utilize the design.

Example of encoder/pid positioning:
https://www.youtube.com/watch?v=KTAoLJEhHUw

Edit 2019.08.10: Updated bom, replaced bearing w