This is remix of Think3DPrint3D's J-head Kossel fan duct for a 40mm fan. I adapted it for the E3Dv6 hot end, added a flange with screw holes for mounting my Mini Differential IR height sensor board (see https://miscsolutions.wordpress.com/mini-height-sensor-board/). I also closed off the bottom to stop the fan blowing air around the nozzle so that I can print ABS.
The tabs for mounting a print cooling fan ought to be repositioned to account for the greater length of the E3D hot end - or preferably, a duct for the print cooling fan should be added.
Note: This design is for version 1.0 sensor boards (all boards shipped prior to July 2015). Version 1.1 boards are slightly smaller and use a different design, see http://www.thingiverse.com/thing:939909.
The sensor board fits on the front of the fan duct, below and slightly behind the fan, with the component side of the board facing the nozzle. The 3-pin Molex connector supplied with the board is too large and fouls the fan, so instead I soldered a 3-pin straight header to the back of the board to make the connections. The E3D is oriented with the longer part of the heater block at the back, away from the sensor.