Railcore XRAT (X Rail Alignment Tool)

NOTE: This thing has been semi-superseded by the [XRAT 2.0](https://www.thingiverse.com/thing:4435803). The old design still works fine, but if you're working on a new build, I would suggest considering the 2.0. That said, it is a slightly harder print and does require additional hardware, so I'm leaving the original design available for those that would prefer it.

This is a screw-driven adjustment tool for the X linear rails of the Railcore II.

End caps are placed over the ends of each X rail and top caps are mounted to the top extrusion of the printer. This provides a known reference for rail height. With the rail loose on the extrusion, tightening the drive screw will raise a given end of the linear rail, while loosening it will lower it.

Because M3 screws have a known thread pitch of 0.5mm/turn, we can roughly estimate rail adjustment based on the number of turns:

|Turns|Travel|
|---|---|
|1|0.5mm|
|1/2|0.25mm|
|1/4|0.125mm|
|1/8|0.0625mm|

Etc.

Note that beca