QUBD 3up Right Gantry Mod

With this addition to the QUBD OneUp/TwoUp Carriage and Bowden mount by express405, I was able to make express405s remix of the OneUp/TwoUp X-Gantry Replacement by StefanBurger work with my 3up.
I simply added an extension and a z-nut holder to the original part by StefanBurger. The z-nut holder matches the height of the left z-nut holder on the express405 remix.