About this 3D model

As you see it's a sensor holder for a optical sensor. http://www.reprapsource.com/oe-r1 First you make a rough adjust by unlocking and locking the Sensor on the Z rod guide. You unlock by pressing it down, you lock by pressing up till it holds itself. The fine adjustment is done with the adjust screw. Don't forget to put a spring on the M3 - Screw. Changes: trigger_part_02 -v3: improved fitting for the nut