Ultimaker 3 : PVA filament stuck in feeder

[niamor2 1]

Hi everyone,

 

I'e got a serious problem with my last print with PVA on my Ultimaker 3 : the material stopped extruding after 1hr, and while trying to unload the PVA filament I realized it was stuck in the feeder. Then I removed the bowden tube at both ends, removed the PVA filament from the printhead, and cut the filament under the feeder. But I still couldn't remove the filament, whatever side I pulled on :

 

 

 

I guess that might be caused by a degradation of the filament by ambient humidity : the spool was left out in the open air for more than one month. But I still don't know how to remove the filament from the feeder. May be I could try moistening the filament in the feeder to soften it and remove it more easily ? Or will I have to disassemble the feeder completely ? Any ideas ?

 

 

Thanks !

[gr5 2,071]

First cut the filament a few cm above the feeder.

 

Did you squeeze the lever on the feeder?  Lift that lever up by squeezing with some fingers on the top of the finger and some on that lever.  Also consider printing wedgebot asap:

https://www.youmagine.com/designs/wedgebot-for-ultimaker2

[niamor2 1]

11 hours ago, gr5 said:

Did you squeeze the lever on the feeder?

 

Yes I tried but it didn't change anything. Squeezing the lever or not, thye filament remains stuck...

[Ghene 24]

30 minutes ago, niamor2 said:

 

Yes I tried but it didn't change anything. Squeezing the lever or not, thye filament remains stuck...

 

I can see that your feeder is really tight and that is the cause of the ground up filaments.  Loosen it up a bit. Turn the screw so the marker is at the top. 

Get a nylon paint brush and vacuum cleaner. Remove the bowden tube.
Then try to dislodge the ground filament while sucking them out.

If that fails, try this... 
https://ultimaker.com/en/resources/50688-clean-the-feeder

[niamor2 1]

1 hour ago, Ghene said:

Get a nylon paint brush and vacuum cleaner. Remove the bowden tube.
Then try to dislodge the ground filament while sucking them out.

If that fails, try this... 
https://ultimaker.com/en/resources/50688-clean-the-feeder

 

Thanks for the advice, but I already removed the bowden tube, and I couldn't remove the filament no matter what. So I tried your last solution, and here is what I found :

 

 

I don't understand how that could happen, but it seems the filament folded inside the feeder... explaining why I couldn't remove the filament manually !

 

So I finally extracted the filament successfully, and launched a print with a new PVA spool : everything seems to work properly !

 

Conclusion : NEVER try to print with a PVA spool that remained a long time in the open air !

 

[Ghene 24]

Phew! I'm glad it worked out. I better vacuum seal my remaining PVA filament then

 

[kmanstudios 1,120]

37 minutes ago, Ghene said:

Phew! I'm glad it worked out. I better vacuum seal my remaining PVA filament then

 

With a generous supply of desiccant.

[niamor2 1]

13 minutes ago, kmanstudios said:

With a generous supply of desiccant.

 Thanks, I will try that !

[gr5 2,071]

PVA and Nylon need to be kept quite dry.  Especially nylon.  I don't leave my PVA on the printer overnight if it's not printing.  I keep it in a sealed bag.  Whenever I get new filament with new dessicant I move the dessicant packet to my nylon and pva bags as the PLA really doesn't need it.

 

You can tell if PVA is too wet (or any material) because it sizzles and pops while printing and comes out more snowy than clear (lots of micro steam bubbles).  You can "repair" the PVA by heating it but it gets soft at 65C so I wouldn't heat it beyond 60C.  You can put it on a heated bed at 60C with a towel over it for 10 or 20 hours.  I suspect that will work.  Assuming that's the problem.  PVA is annoying in that if it gets too dry it also fails (gets brittle).  60C should be safe.  You want I think around 10-20% humidity.

 

Using this slider: http://www.dpcalc.org/

Let's assume in your building the temp is 20C and humidity is 60% then the dew point is 12C.  Crank temp up to 60C using the calculator above and slide the humidity down until you get 12C dewpoint still and your new humidity is about 7% (heating air won't change the dewpoint but it lowers the humidity).  I'm not sure this math is the correct way to calculate things for drying filament but it's what I use.  That should be safe I would hope.  It just might take many hours for the water to escape the pva - especially on the inner turns of filament deep in the spool.  Anyway I've used this trick (heat it to 110C for nylon) to dry nylon to great success.

[kmanstudios 1,120]

14 minutes ago, gr5 said:

Using this slider: http://www.dpcalc.org/.....

That should be a sticky ? Easy to find for all.

[niamor2 1]

17 hours ago, gr5 said:

PVA and Nylon need to be kept quite dry.  Especially nylon.  I don't leave my PVA on the printer overnight if it's not printing.  I keep it in a sealed bag.  Whenever I get new filament with new dessicant I move the dessicant packet to my nylon and pva bags as the PLA really doesn't need it.

 

You can tell if PVA is too wet (or any material) because it sizzles and pops while printing and comes out more snowy than clear (lots of micro steam bubbles).  You can "repair" the PVA by heating it but it gets soft at 65C so I wouldn't heat it beyond 60C.  You can put it on a heated bed at 60C with a towel over it for 10 or 20 hours.  I suspect that will work.  Assuming that's the problem.  PVA is annoying in that if it gets too dry it also fails (gets brittle).  60C should be safe.  You want I think around 10-20% humidity.

 

Using this slider: http://www.dpcalc.org/

Let's assume in your building the temp is 20C and humidity is 60% then the dew point is 12C.  Crank temp up to 60C using the calculator above and slide the humidity down until you get 12C dewpoint still and your new humidity is about 7% (heating air won't change the dewpoint but it lowers the humidity).  I'm not sure this math is the correct way to calculate things for drying filament but it's what I use.  That should be safe I would hope.  It just might take many hours for the water to escape the pva - especially on the inner turns of filament deep in the spool.  Anyway I've used this trick (heat it to 110C for nylon) to dry nylon to great success.

 

Thanks a lot ! For now I will try putting the spool in an airtight pouch with dessicant for several days. If that doesn't work I will try the heated bed.

[kmanstudios 1,120]

I would try the heated bed, then put into sealed bed with desiccant. If there is a lot of moisture in the PVA, it could take a while to get from the core to the edges. Also, it could be enough to overwhelm the desiccant.