This Version of a Z-Axis Adjuster allows to fine tune the z-Axis Endstop Switch. It has the advantage that it is screwed to the ultimakers case and has very thight tolerances.
This Version of a Z-Axis Adjuster comes as three parts, of which the AxisHandle (a variation of http://www.thingiverse.com/thing:22819) is optional.
Needed are the Object AxisGuide and AxisSlide plus a 30 mm Bolt and a SafetyNut. (See picture)
Because I designed it in Blender with the help of the metric system, the stl's are too small to print straight out of the box. In my experience when printing the files with factor 1005 it will be perfect.