FT5 Bowden tube filament holder, no fittings required.

After making my Bowden tube spool and holder, and not totally happy with how the original design of this had slop and actually began to wear my extruder lever, I edited this thing to use a 6mm OD tube, press fit, should be tight enough to hold tight, but loose enough that you can easily remove the tube to change filament.

Works great for me, but if you want to adjust how tight the tube is held, simply plop the part in warm water or use a heat gun and gently push the tube into it.