Kossel fan duct and IR sensor v1.0 mount for E3Dv6 hot end

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 prefe