I’m just about had it with this issue. Right now half the time I can’t even use my printer. Does a model require retraction? Forget about it, my printer jams up, the filament ground to dust. I’ve lowered the tension on my feeder, been told by support to try raising it instead, cleaned my the feeder, cleaned the head, done a firmware update, started using the most recent version of Cura, the only thing that made a lick of difference was replacing the entire feeder assembly with a brand new one. That lasted a month, now I’m right back where I started. I’m not even able to load filament right now because I get the same problem. I get a little squirt of filament out when I change material, I set the printer up to print, than nothing just ground down filament.
Is cura set to work with 3mm or 2,85mm or 1,75mm? Try to extrude cleaning filament by hand through the heated hotend to unclogg it, I’m pretty sure that a partial clogged is the reason for your issues. What material and temperature were you using and from which brand is the filament?
I had this problem with my UM2 (although not as bad as you). My solution was slightly loosening the 4 bolts half a turn, that hold the feeder on the back. No idea why this helped but it was what someone suggested to me.
I have already cleaned the hot end. I can pass some metal floss through with out difficulty at this point. I was printing at 240 with green ABS from makergeeks. Cura is set to the default settings for an Ultimaker 2 which is 2.85
you don’t say what type and make of filament you are using and the temperature you are printing at.
I would suggest doing several atomic pulls to clear your head and nozzle first, then with the Bowden tube disconnected from the head, head up the head to the minimum suggested temperature for the filament and then gently manually pushing a fresh length of filament through the head to see how it flows, increase the temperature 5 degrees and try it again, do this a few times to access the force needed to extrude some material, this will help to find a nice temperature.
i would then cut off any length that has been through the feeder and has been marked so you have a fresh length. Check the material flow rate is it set very high if so reduce it too 100%, and check your speed, slow is the key when 1st starting. See how you get on printing a UM robot, about 40 - to 50 minutes to see how it goes, (PLA at about 210 to 215’C).
if you have a UM2 and can get it to start printing after the above I would recommend one of the first things to print is Roberts modified feeder, this can help solve a lot of feeder problems. ( when running normally you will see some indication patten from the feeders but not too much or it distorts the soft filament that then jams in the coupler before it can get to the nozzle) you want minimum friction from the feeder to maintain extruding, with just the occasional click back so as not to grind.
I have cleaned the hot end multiple times. Attached is a picture of the first Atomic pull I did. There is no debris on the end. At your suggestion I redid this step 5 more times, same result. I am using ABS plastic and attempting to print at 240. When I change filament I get the usual little bit of filament coming out. I tell the machine we’re all good, then when I attempt to print nothing comes out the nozzel. The second attachment is what the filament looks like after an attempted print job.
Looking at the photos, I would say that the filament is jamming in the nozzle area, looking at the picture showing the filament end from inside the nozzle, you should NOT have that swaged type form where there is that flared out piece of plastic! it should measure 3.2ish mm all the way to the point. if there are any bulgies over say 3.3mm this will cause the plastic to jam, and the feeder to grind.
Also check that the Bowden-Insulater-nozzle bores all line up perfectly concentric to each other this is also a cause of filament jamming leading to the grinding you are getting…
so to some up, investigate the cause of the flare of plastic in the nozzle end. this I believe is your cause.
I had this problem and found a solution. The reason why it was grinding on mine was because the filament reel was too tightly wound. Meaning it pulls back from the feeder causing it to grind as it is pulled back and forth. Simple solution is to loosen up the reel itself.
