fuh

Same here (though not with every PLA brand). Seems systematic, very strange. Does anyone have an explanation for it? Maybe fumes of lactic acid (depolymerized PLA)?

Updated the ring design. New in version 8 (vs. version 5): Now easier to assemble.

Update: I was a bit unhappy with the "just hanging" idea because occasionally, the ring slipped off and fell down. So I made a guide thingy for the ring. Updated on Youmagine.

Update: I have a suspicion that it becomes (more) brittle while staying in the bowden tube for a longer time. No idea why. Now I unload the filament whenever I won't print for, say, one day, and I think it's better now. Maybe an idea for you, too.

Soon I will have four empty Ultimaker.com filament spools. Wouldn't it be a waste to throw them away? Any ideas for repurposing/upcycling of the spools? Preferably printable ideas, of course.

Thank you! Looking forward to hearing about your results...

Just hanging. It is held by the filament loop itself, while spreading it. It leans lightly against the feeder.

I found a very simple solution to reverse the bend: Flip the filament spool winding direction and guide the filament around a ring. Like this: Although the image shows a modified spool holder, I tested it with the original spool holder and I reached 10mm^3/s no problem. (PLA, 210°C, original feeder, 0.4mm nozzle) Get the ring here: https://www.youmagine.com/designs/spreading-ring-for-reverse-bend-filament-feed-for-ultimaker-2

Same problem here with PLA (white) from GermanRepRap.com .

I use my old laptop computer, having a camera, and run Skype on it, with an extra Skype account just for that purpose and set up to accept a call without asking. That's all - very easy, works from anywhere.

Photos will come later.

I noticed that the infill left not only a little ridge where it overlaps with the shell, but also little droplets now and then. First I thought this doesn't matter because it is inside the obect. But then I noticed that on the following layer, these droplets are sometimes dragged to the surface when the shell is plotted, and there they remain as bumps. I simply reduced the infill overlap (in the experts menu in Cura) from 15% to 8% and the bumps were gone. Maybe it's helpful to someone.

I never noticed any improvement with glue stick. I'm printing PLA directly on the glass at 75°C. I found it sticking noticeably better than at 60°C.

And I remember a case (with an UM orig.) where the filament was completely stuck, it could even almost no more be pulled out by hand. All because the printing speed had been set far too high whereby the feeder had caused a lot of deformation and abrasion. Thus the friction was extremely high. I stay with my theory that friction forces after the feeder are the central problem, and those before the feeder are neglectable, compared. Why: The brake effect of pressing material through the nozzle must be by far higher than the brake effect of spool unwinding, and these brake forces are the cause for the friction forces. Just normal engineering logic. How much is the deformation by the knurled wheel, anyway? Could it happen that it increases the maximum filament diameter to more than the tube inner diameter? Then the friction would increase overproportionally. If the increased counterforce of the feeder wheel in turn causes deeper filament deformations (just a possibility, not an observation) then we have an escalating problem!

I'm not sure if everybody has noticed my findings about filament friction which allowed me to at least double the extrusion rate before underextrusion occurs. http://umforum.ultimaker.com/index.php?/topic/5454-ultimaker2-reduce-filament-friction-in-the-bowden-tube/&do=findComment&comment=52713. It might help.