[Bowden tube comes loose in mid-print]

On 7/7/2020 at 5:08 AM, SandervG said:

A lot of good advice here. Perhaps a summary would be helpful. If your bowden tube pops out of the collet do the following: 

- Push down the collet and pull out the bowden tube. See if there are any significant scrape marks on the sides. 

- Remove the collet from the socket and inspect the insides. Do you see 4 equal (small) blades in there? 

 

If the collet does not 4 equal blades you should contact your reseller for a replacement. If your bowden tube has significant scratches on its surface and your collet still has 4 blades, then you can try to cut off ~4mm of the bowden tube so the blades can grip a new and fresh part. Keep in mind: 

- Do not do this too often. When a bowden tube gets too short there will be other problems concerning the filament passing inside.

- If you decide to cut it, cut it straight. If the bottom is not flat there can also be extrusion issues over time where the filament can expand due to heat and pressure in that small area where it is not touching. 

 

It is not a bad idea to replace them once a year or so to ensure all is in good condition. Check out the maintenance schedule for your printer for more information on this topic.

I had this issue today, and your post was really helpful!

But, since this is a known issue that seems to affect many users, couldn't Ultimaker implement some kind of sensor just before the print core to check for material flux?

If the bowden tube slips on a Friday night, the printer will be a mess on Monday morning, and the initial part of the print will be lost.

It would be great if the printer just stopped itself when this happens, just like it does when the material spool is empty.