About this 3D model
I mostly hacked Jonas Kühling work, so all the credits go to him what did I do? I converted from LM8UU to LM12UU and from M3 screws and nuts to M4. I also made the whole thing thicker and put a bigger mouthplate with added nut holders. It helps me greatly to glue the nut in the nut holder and then just turn the screw. I also added a small end stop for the LM12UU. As I will use those holders to mount my Z axis in my CNC I thought that maybe the added support is worth the extra plastic.