A rough and ready (functional, not pretty) bracket that slots over the top of an i3 single metal plate to hold an Airtripper Bowden extruder (http://www.thingiverse.com/thing:126778).Print the mount and attach to one of the Airtripper Bowden mount tabs with an m3 screw and nut (you will need an m3 washer that is larger than the hole in the Airtripper mounting tab - I used a repair washer because it was all I had to hand). Then slot the whole assembly over the top of your single plate metal i3.