3D Printed Linear Rail

Since starting to build a Dollo3D for myself, I've been interested in testing how far one can get with 3D printed parts. One of the problem areas with Dollo has been the Z-axis and for now I've resorted to using metallic lead screws. However, I didn't want to buy linear rails, I wanted to print them. Also I wanted the rail setup to be extensible, even though the lead screw isn't (yet). So came up with this setup where the slide has kind of spring mechanism so tolerances don't need to be 100%. Also it slides quite easily, making it a good option for Z-axis rail as it usually doesn't move that fast.

Source available in here: https://github.com/spegelius/Dollo/blob/master/NEW_long_ties/rail.scad

I've been running 4 ~50cm beams for something like 6 months now and the setup is still going on strong. Even with not so straight lead screws, the prints are coming great regards Z-axis. Lubricant strongly advised, I use PTFE based spray.

There are of course things to improve, like the jo