Filament broke in feeder. Remove feeder or push new filament in?

[tomkooij 0]

While changing filament, it turns out the PLA broke around the hobbed bolt. The feeder reversed but the filament is still in the bowden tube from feeder to nozzle.

Do I remove feeder(cover) and pull out the filament? Or do I push new filament in and let it push through? (I'm thinking option 1 is a little more work, but a clogged nozzle due to option 2 is a lot more work...)

 

[takei-naodar 0]

Also take into account that with option 2 you loose the rectraction...

 

[DidierKlein 729]

I'd say it depends on the size of the broken filament.

It happens to me most of the time when i change filament, usually there's a little "blob" of filament that stays in the feeder. I was afraid first time but i tried to put in the new filament as if nothing was in the feeder. And the new filament simply pushed the blob all the way down to the extruder.

As a matter a fact i had this little blob for my first filament load (out of the box) and i had no problems

 

[closedcircuit 1]

That happened to me last night (on an UM2). I pushed the broken filament through, let some of the material flow through the nozzle and had absolutely no problem.

 

[gr5 2,172]

Be aware that when you remove the 4 screws on the feeder, the stepper will fall.

 

[smorgana 0]

I had the same situation. Except in my case I ran out of filament during a print, so a piece of filament got stuck all the way from the feeder to the nozzle. You can't have the feeder reverse the filament out because it is just past the feed gear.

Also on an UM2 you can't just push in a new filament while powered up because the stepper is energized.

What I did was cut the new filament end flat so it would have the most surface pushing against the broken piece. and manually fed it into the feeder while turning the dial to advance the filament in the "move material" menu option.

I did that just enough to get extrusion out of the nozzle, then I printed something unimportant to use up the broken piece.

As others have noted, until you get past the break, retraction doesn't work so the quality of the part suffers.