Lulzbot TAZ 6 X-Axis Levelling Tool

Lulzbot say that one should level the X-Axis by measuring from the top of the axis rods to the top 20mm rails.

I've always found this awkward to do and puzzling as the point of reference should surely be the bottom rails of the printer where the Y-Axis is attached.

Hence this simple tool (or tools as you'll need to print two of them).

*How to use them*

Jog the print bed to the back of the printer so it's out of the way and jog up the X-Axis so that you can insert the two tools into t