Error with PLA "The material for feeder 2 appears to be empty" after switching nozzles?

[paulchod 0]

Hello,

 

my first post here. I am relativly new to the 3D printing, so bear with me.

I am trying to print a part from PLA (ultimaker black), but it stops printing with an error that says "the material for feeder 2 appears to be empty" or something among those lines.

I noticed that I get this error when the printer changes the nozzle, from printing the real part to printing a support for that part. Support is printed with ABS yellow, also ultimaker brand. I noticed that because when I tried to print it yesterday, I used priming tower when it changed the nozzle to print with. After each time it printed on the tower and went back to print the part with PLA it gave me this error message. I should probably also mention that I print with default speed settings, temperature at 215 C, glass bed temp. at 85 C.

Then, I tried to print a test block, without any supports from other nozzle, but I got the same error aswell. Also, the print looked "meshed", as in looking through a very fine grid.

I did some looking around on the forums and I found out that retraction could be the problem (I didnt even knew what retraction was, so I had to google a little bit more to find out what it was). I checked my filament and it was grounded up, but only on a small portion of the whole filament, so the whole retraction thing made sense to me. Anyways, I disabled the retraction for test cube, and it printed fine. Finally, I thought, I can print the real part. It was getting late, I set the real part that I wanted to print, waited another hour just to make sure it wouldnt get me the error and left for home feeling confident that I fixed the problem.

And if it would be fixed, you wouldnæt be reading this. This morning I came to see the print and lo and behold, I got the same error message, about 1\3rd way into the print.

 

What could cause this problem? Tension is set on the middle, retraction is limited to 10 times per 5 mm, speed is default, temps are at 215 on the nozzle and 85 on the bed (not that it should matter, right?).

 

I clicked continue when I just came and just sat next to the printer while I was writing this. It seemed to print fine for 15 minutes, I think it even printed a few layers of support material. But after 15 minutes it gave the same error.

 

Sorry for my english mistakes

Hole for wing M4.STL

[paulchod 0]

Update: It appears that the filament end that is closer to the hot end was partially melted and got stuck in the bowden tube, making it impossible to move it, even with the pliers. I had to cut it. I wonder what caused it. I have some theories about temps being too hot and too much retraction going back and forth, but I am not sure about those either.

I changed the nozzle to AA 0.8, I got the error much more often, like almost every minute.

I reluctantly turned off the flow sensor and it seems that the error no longer pops up. I will check on the print tomorrow morning

Edited September 30, 2021 by paulchod

[paulchod 0]

Update 2: it appears that the part finished fine without any problems. Does this mean that all the problems are caused by the flow sensor?