About this 3D model

This replaces the standard Rostock Bowden hotend mounting that used the M8 nut. I did not like the way it threaded on and would come loose. I modified this derivative from an Ultimaker bowden assembly and the original Rostock and this is what I ended up with. It works with a 4mm tube. The insert / collet could be a little tighter but I just used a piece of tape around the bottom of the tube.