For my Carbonoid D1 printer I derived the design of the end effector from the work I did for the OpenBeam Kossel Pro. This end effector is designed for the E3D Volcano hotend. For the 1.75 mm and 3 mm versions you only have to print a different holder clip. The end effector base also has a 18 mm hole for an inductive bed sensor.The E3D V6 is also supported, just print and use the fan ducts for the V6.
Update 04-18-2016: Added a E3D V6 version of the end effector base that supports a SN04-N inductive bed sensor.
Technical
18 x M3 threaded brass insert
1 x M5 threaded brass insert
1 x M5 x 50mm hex key screw (cable mount)
2 x M3 x 8mm hex key screw (fan duct)
12 x M3 x 16mm hex key screw (fans)
6 x M3 x 20mm hex key screw (arms)
4 x M3 x 25mm hex key screw (filament fan ducts)
1 x 18mm NPN NO inductive bed sensor
1 x 30 x 30 mm fan (for fan duct, comes with the Volcano)
2 x 40 x 40 x 10 mm fan (for filament fan ducts)