A new adjustable endstop for Z axis

Just finished and tested a new adjustable endstop for Z axis
Now it is possible to adjust the endstop with only a screwdriver ( wrenches are not necessary ) 
Turn the M4 bolt to adjust the zero position.
All the parts have been designed with Design Spark mechanical, then adjusted with NetFabb ( to remove the incorrect mesh ) and then printed with Repetier / Slic3r.

Here the complete vision

a better image of the parts

board plate that attach the original Prusa Z endstop plastic

plastic part that sustain a M4 nut, developed with Design Spark mechanical

Here the same part, adjusted with Netfabb