Filament broke off in tube

[nebogipfel 0]

The printer at our library had not been used in a while. When I tried to change the color, the filament snapped off inside the tube. Now it goes from the printhead to several inches above the feeder. My question is, how do I get it out? Do I take off the nozzle (while heated) then wait for it to cool and push it backwards with some wire? I really don't want to take the printhead apart to get the teflon tube out.

 

Oh wait, can I put some good filament in behind it? But then will the loading run for too long (it will assume that the tube is empty to begin with) and make the situation worse? If loading more filament to push it forwards is workable, I can just print a couple tiny things until the bad filament has all been pushed through the nozzle.

 

Also, do I need to adjust the feeder gear with the screw? Is that why the filament broke?

 

Whee this is fun [sad face].

[NBull 14]

I would disconnect the bowden at the print head and some of the wire clips. so you can pull the bowden off the filament piece. then manually heat the printhead til the filament can be pulled out. Assuming theres still a bit of filament left over the print head when the bowden is removed. so you have something to pull on.

 

(Disclaimer, its a long time since i have worked with the u2, so there might be a better way to do it)

 

Edited December 5, 2019 by NBull

[Smithy 1,146]

Depending on your situation where the filament is broken, remove the Bowden from the print head only, or on both sides. Then heat up the nozzle to 200° and pull out the filament. That's it, no need to do more.

 

I guess the filament broke just because it sits too long in the tube and got brittle. This is quite normal for PLA.

[AndersK 59]

Do as Smithy suggest. Printing with poor material can clog your nozzle giving a lot more grief and work to fix.

Dont ask how I know 😉

[ultiarjan 1,223]

6 hours ago, NBull said:

I would disconnect the bowden at the print head and some of the wire clips. so you can pull the bowden off the filament piece. then manually heat the printhead til the filament can be pulled out. Assuming theres still a bit of filament left over the print head when the bowden is removed. so you have something to pull on.

 

(Disclaimer, its a long time since i have worked with the u2, so there might be a better way to do it)

 

 

to be clear; take out the horseshoe clip (the blue thingy) then push down on the white thingy while pulling out the bowden tube.... Works the same on the feeder side  of the tube...

 

[geert_2 560]

To make removal of the clips easier, you could use these, or design a similar one yourself. Then it is piece of cake.

 

For the model, see here (and then scroll down a bit):

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

 

In my own machines, I have a new design that is a bit optimised, but I haven't uploaded it yet. But I used these for 3 years; and they are reasonably good.

 

 

 

[nebogipfel 0]

Thank you folks! I had no trouble getting the clips off at both ends. Then I manually pushed the broken filament through with some good, just enough to get hold of the bad and pull it out. Back to printing!

[Smithy 1,146]

Thanks for the feedback!
I'm glad it worked.