Heating Issue?

[ozzyd94 0]

The past month or so I am having extreme issues with longer prints. Every print that is longer than a few hours I come back with the print head "printing" in mid air with no filament coming out and the filament that should have been pushed out coiling up near the air manager with the Bowden tube disconnected from the feeder. 

I thought it may be an issue with our print core so I purchased a couple new ones and the issue continues. I also tried using extruder 2 as the main extruder to see if that resolved the problem but that didn't fix the issue either. I know the extruder is clean and that the feeder is pushing the correct amount of plastic through so I am kind of at a loss of what to do next. We do a lot of prototyping and need to get back to be able to print larger parts.

 

Any print say an hour or hour and a half and less prints with no issue but any longer print will fail. 

What would cause the print core to not hold temperature and how do I fix it?

[IRobertI 521]

If the bowden is popping out of the feeder you first and foremost need a new collet for the bowden. There has been a number of collets that have had issues with the little "teeth" inside it not gripping the bowden tube good enough. Either get in contact with your reseller and they will most likely send a new one to you for free. Or just buy one (they're dirt cheap).

[ozzyd94 0]

9 minutes ago, IRobertI said:

If the bowden is popping out of the feeder you first and foremost need a new collet for the bowden. There has been a number of collets that have had issues with the little "teeth" inside it not gripping the bowden tube good enough. Either get in contact with your reseller and they will most likely send a new one to you for free. Or just buy one (they're dirt cheap).

Yeah TBH the only reason the bowden tube is popping out is due to there being so much filament feeding out on a longer print and it now flowing through the nozzle and it having nowhere to go. The first time this happened I came into work that morning during a 30 hour print and there was about 15 feet of filament probably spooled up inside the enclosure above the print head so at the top of the feeder it disconnects the bowden tube as the material continues to flow.

In "normal" conditions I haven't had any issues with the bowden tube.