Basically this is a long screw and nut that can be used to support pretty much whatever needs supporting. In my case I made this to support my GPU since I noticed some deformation in the PCB from sag. These jacks use a metric trapezoidal thread similar to acme except metric. As a result of this I do recommend using lower layer heights for a smoother screw. 

Compressed length of the model is 60mm. For full extension I'd recommend at least 2-3 threads engaged so that eats about 7mm leaving a max length of roughly 95.5mm.

I've included the CAD files so it can be edited. It should be completely parametric. 

For printing I'd recommend the following settings:

• PLA is fine for most cases except where temperature is higher. For those cases I'd recommend PETG, ASA, or ABS. Ultimately choose what works best for you. I used PETG. Flexible materials are not recommended.
• 0.15 layer height, my prototypes were printed with a 0.2 layer height with the final iteration printed with 0.15. This results in a smoother thread.
• 2-4 perimeters, my prototypes were printed with 2
• Infill is up to you, I'd recommend at least 15% and there's no real reason to go higher than 50%.