3D printed linear actuator build

This is a simple, easy to build, linear actuator. I designed the actuator so that supports are not needed,
get the files: www.thingiverse.com/thing:3285418

In action video:    • 3D printed linear actuator  

other things you need:
-12(1/8x1/2 machine screws)
-6(1/8x3/4 machine screws)
-2(1/8x1 machine screws)
-1 washer that fits on the screws
-1 (5/16 steel threaded rod length of 4 3/4)
-2 nuts that fits on the threaded rod
-yellow geared hobby motors