This is a quick n' dirty mount setup for putting a Bondtech BMG extruder on the excellent extruder from jasonatepaint. Possibly other direct-mounted extruders as well.
The extruder is only fastened to the mount by the groove-neck so you need reasonably good dimensions on your printed part.
Before fitting the BMG extruder, install the mount, put a PTFE tube down the E3D-V6 and put a mark 2mm above the mount, cut it, and it'll mate perfectly once the BMG is in place.
I have used this for half a roll (0.5kg) so far, and it's seems sturdy enough!