Had issues with the included Bowden fittings not holding the Bowden tube anymore. Made these in fusion360 and so far, working well for me. the Bowden tube screws into the internal thread, and there's a 2.8mm hole for a 3mm grub screw for extra strength. (be careful not to over tighten and restrict the filament path inside) please let me know if any fine tuning can be made.
UPDATE: 10th/Nov/2019: Added V2 stl. Adds a recess for a 4mm nut. far superior grip on the Bowden tube. thread tube leaving 5mm above nut. you may have to drill the ID of the tube to allow free running of filament after threading through the nut. (remember to clear the tube after drilling so you don't push anything down the tube that might clog the hot end)