Robo3D: Leadnut adapter with z-axis limit switch

[RoBo3D Autolevel via Mike Kelly](http://www.thingiverse.com/thing:349935) is very very nice. This adapter is for modified Robo3D with lead nut and screw, able to buy from [Maker's Tool Works](http://store.makerstoolworks.com/motion/z-axis-lead-screw-and-nut-single/).
Uploaded file is for right side. Please mirror by your slicer for left side.