Bowden tube popping up

[truckle 0]

I've just noticed that during my current print the Bowden tube has 'popped up' from the hot end leaving a gap of about half cm between it and the hot end. I can just see the filament going in unsupported. This happened earlier, so I aborted the print and re-pushed in the tube and made sure the collar was tight, up and the little insertion spacer was pushed in. Re-started the print and now it's happened agin, about 15 mins into the print.

It is actually still printing the bottom layers perfectly well, but as it's a 9 hour print I don't know what will happen later.

Has anyone come across this before and do you think the current print will go ok? I am not sure how essential it is for the Bowden tube to be firmly pushed into the bottom of the extruder part.

[illuminarti 18]

It's absolutely vital for the bowden tube to be fully inserted to constrain the filament path, and prevent any deformation of the filament before it goes into the hot end - especially when the print starts doing retractions.

The outside of the bowden has probably abraded away where the clip grabs it, so that it cannot properly grip any more; alternatively the clip itself may be damaged so it doesn't grip properly.

I recommend removing the bowden tube from the hot end, and cutting off a few mm, so that the clip will be gripping fresh plastic again when it is reassembled. Follow http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/?p=40399 to re-insert and fix the Bowden. Before reassembling, look down into the clip, and make sure that it looks ok, and the metal bladed grippers just inside the black plastic block don't look damaged.

 

[truckle 0]

Thanks, I re cut the Bowden tube and now it doesn't move when I pull on it fairly hard, so thanks for that! I'll test it when I've sorted my fan problem out.

[braddock 1]

this might be obvious, but if ever you need to removed the bowden tube, pull the print head apart and pull the bowden tube all the way out forwards, not back against the grain of the little grippers in the collar, so they don't shave the tube down at all.