I used the Carrier from (http://www.thingiverse.com/thing:981239), to make an complete one-piece extruder with carriage integrated for the pangu/prusa I3. (ex k-extruder) I have made it especially for the E3DV6 hotend. Optional proximity switch holder is also taken care of in this design. The proximity sensor is used together with an Aluminium hotbed, because the glass bed is to thick to measure inductivity for this sensor. Make sure to print with supports.