E3d v6 openbuilds large gantry support with pl-08n sensor

This is my version of an e3d v6 hotend support for an [openbuilds V-slot plate](http://openbuildspartstore.com/v-slot-gantry-plates/) on my [Tronxy X3 printer](https://www.aliexpress.com/item/2016-Best-Tronxy-X3-DIY-3D-Printer-kit-Aluminium-Structure-machine-Reprap-prusa-i3-3D-printing/32706377431.html) .

The particularity of my printer is that the gantry is hung vertically, not horizontally, with the belt running in the top and bottom part of the rail, under the wheels.
Which made every oth