Hello, I am trying to build myself a 3D printer and have an extruder/hot end question. I ordered and now have in my possession the following: -Bulldog XL (http://www.reprapdiscount.com/mechanics/64-bulldog-xl-extruder.html#) -Bulldog XL E3D Mount (http://www.filastruder.com/products/e3dv6-bulldog-mount) -E3D v6 1.75mm Universal (http://www.filastruder.com/products/all-metal-e3d-v6-hotend) However I am having some issues putting it together. The hot end comes with this plastic like fitting in it that where I guess the PTFE tubing goes (which the E3D documentation says is mandatory). However with the little plastic fitting in the hot end, it won't fit in the Bulldog. Does anyone have any experience with this? Do I really need the PTFE tubing (not really an ALL METAL hot end at that point) and that little plastic fitting on top? Thanks in advance for any help.