Hi, did it ever happen to you that the bowden coupler on the hotend side let the bowden tube slip out? Mine always has a bit of wiggle room because I cant get pull the little black ring up far enough because of the way the hotend is mounted in my effector, but the 0.5mm of wiggle room / backlash never bothered me, but yesterday the whole bowden tube said good bye and slipped out mid print, so i wonder if the coupler is worn out or I have to secure it more tightly? Cheers
Once the tube is pressed down hard enough in the coupler it should not get loose. The reason you should pull on the black ring while inserting the tube is to remove slack so the system works more accurate. Check your tube for deformities or damage and if so remove a couple of millimetres with a sharp knife and insert it again
As per build instructions when assembling the hotend ptfe tube and bowden it's possible to hold the clip up using the loop of a paperclip.