Ultimaker 2 underextruding, atomic method seems to not help

[oddoutput 7]

since a few days i have the problem where my ultimaker stops extruding after some time.

I've tried doing the atomic method, but it didn't help.

Now, i'm also not sure if I really did anything wrong, because when I pull out the filament when doing the atomic method, i don't get a coneshape, just this

I don't know if that's also a sign of me doing something wrong or anything.

The latest print I tried wasn't even able to make the outside ring, with the line being too thin to just being nothing.

[DidierKlein 729]

I think you can do the atomic method a couple of times more.

If it always comes like this then drop the temp a few degrees when doing the cold pull, when you get a clean coneshape pull you can assume the nozzle is not clogged

[oddoutput 7]

I tried putting the temperature a little bit lower for the atomic method cooldown and now i get a tiny cone shape so that's something I guess

[Sensi-Jense 0]

Is your motor ticking? I had problems with under extrusion, motor would tick and stop feeding for a moment.

Increasing the current to the feeder motor in the maintenance menu worked for me.

[oddoutput 7]

The motor doesn't tick and the problem is still here.

It just stops extruding after a random amount of time.

[gr5 2,170]

since a few days i have the problem where my ultimaker stops extruding after some time.

How long did you have your printer before this started happening? Are we talking a few months? A few years?

What country do you live in (please update your location settings).

theory 1: That black stuff is very worrying in your cold pull. You probably have a thin layer of gunk inside your nozzle which is making it smaller. Could that black stuff be pieces of of black nylon from the feeder? You might want to replace the nozzle. Or take it out and burn everything out of it and even maybe soak it in acetone for a few hours. Or get a Olsson block and new nozzle.

theory2: teflon Isolator - these kind of die after a while. Easy to test if you have an olsson block as you can push filament up from below through the isolator to feel the friction.

theory 3: Some prints have too many retractions two close together and the filament gets ground up. Next time this happens pull the filament out a bit and check the portion that was in the feeder to see if a bite has been taken out. Or if it is flattened. Some prints I've had to reduce retractions by setting the min-distance to .3mm (that means no more than about 15 retractions for a given spot of filament).

theory 4: People in warm climates have issues when air gets above 30 or 35C because the filament gets soft at the extruder. Is your room temp higher than a few months ago? The fix is to put a window fan blowing on the extruder to keep the shaft 5C cooler.

I can come up with more theories if you rule these out.

[oddoutput 7]

We've had it for around 3 weeks now.

I'm located in the Netherlands, so I don't think that the filament would be a problem (next to that, the week I got it it was really hot outside and it printed just fine.)

The filament also doesn't seem ground up.

The black stuff seems to have been removed with the atomic method but I don't know if it's definitely removed.

Also if my search was right, an Olsson block is a nozzle block where you can unscrew the nozzle ?

[gr5 2,170]

Also if my search was right, an Olsson block is a nozzle block where you can unscrew the nozzle?

 

Right.  It makes it much quicker to change nozzle sizes, change to a new nozzle (they are about 11 euros each) or take it off for more careful cleaning.  Even though the nozzle is mostly clean it might have some baked on crud along the inner walls.  

So theory 2 and 4 are probably wrong.  If you have a hypodermic needle, or acupuncture needle or 0.4mm drill bit, then you might be able to clean the nozzle out a bit with something like that.  In the past I've placed the nozzle in a gas flame holding it with pliers but be careful not to melt the brass.  There is a huge temperature difference between burning out everything in the nozzle to ash and the temperature where brass melts.  But it is still possible to melt your heater block so I would remove from flame often and check to see all remaining residue has burned away.  Then test by pushing some pla through it while it's still hot and still held by pliers.

Edited July 16, 2015 by Guest

[oddoutput 7]

I have not been able to disassemble the printerhead yet because of the whole warranty thing and I wasn't able to contant my seller yet, but I did try cleaning the nozzle more.

When I use the atomic method, I don't pull any dirt out and I don't think I even need a needle because I can actually see the nozzle exit pretty clearly.

But still it suffers from the same problem, just stopping with extruding or not even starting with any extrusion.

I noticed a few times where material gathers on the exit of the nozzle.

The feeder seems to work like it should though (sometimes it doesn't retract the material though, most likely because it's stuck in the nozzle, and I have to help it by pulling on it).

[gr5 2,170]

I have not been able to disassemble the printerhead yet because of the whole warranty thing

 

I don't think you have to worry about that. You are confusing ultimaker with makerbot. The head is designed to be taken apart. You might break something like the temperature sensor but the lesson will be worth the cost of a new one. Every owner of an ultimaker has likely been forced to take apart the head within a month of purchase.

You live in the Netherlands so just give UM a call. They will probably want to know your serial number. I think they provide support even if you bought it from a reseller. The people in support are knowledgeable and great and speak both Dutch and English very well. Calling UM usually works the best for support as they usually answer the phone right away - if you get a recording try again an hour later.

[oddoutput 7]

My dad and I carefully replaced the nozzle today.

Tried to print few things, but with not much succes.

The calibration test that came with the ultimaker was weak and ugly (broke off the poles with very little force).

My own model seemed to go right until the end, and the second one already started with ugly and underextruded bottom layers.

The teflon coupler had a small brim of dirt but we removed that.

I really don't know what could be the problem anymore. The feeder??

[gr5 2,170]

The calibration test that came with the ultimaker was weak and ugly (broke off the poles with very little force).

 

I guess that could be due to underextrusion. Maybe your temperature is much cooler than you think. Many sensors are off by 10C. Try this temperature test:

 

[gr5 2,170]

When you had it all apart you should have tried pushing some filament through the white teflon isolator to see how much friction. I've seen isolators that have over 1kg of force needed to push filament through and that can get worse when under pressure.

[oddoutput 7]

The filament went through the isolator without any problem or force and the nozzle seems to get hot enough

[oddoutput 7]

I let me 7 piece file run this night, only to be greeted by 4 pieces completed, and it ending with this

the nozzle is clean because it's completely new and the nozzle gets hot enough (did that test and the filament already starts melting lightly at 170)

I'm baffled.

Would it be the feeder after all?

[neotko 1,417]

Check as gr5 said the room heat. Weird thinks to check:

- Clean the feeder wheel with a wire brush. In my experience some filaments erode there making the grip of the whell to slip instead of pushing. Best way to check this it's to clean it. And since you are cleanning the knurled bolt, check if it's well screwed.

- Maybe you can remove the bowden to the feeder and insert a filament strip attached to a 20 pounds bag. Correct me if I'm wrong but I think that's how much the feeder should be able to push up. If it slips/skips (tack-tack sound) there's something weird on the feeder tension etc.

- Check the filament diameter with a caliper to be sure it isn't more than 3mm. If it's a good brand material this shouldn't be the problem.

[oddoutput 7]

The room temperature really isn't a problem (it's under 24C now and the first week i had it, it was the hottest week in the netherlands this summer and it worked perfectly.)

We took apart the feeder and cleaned it and also tried putting the tension a bit higher.

None of it helped.

The filament diameter isn't bigger than 3mm (we used around half a 1kg roll before it started acting up)

Just now, my dad tried to reprint one of his parts and it actually came up with a new thing!

 

It just makes a line straight to the edge (any edge) and goes back.

The first time it happend it went to the front and also hit it before going back.

Edited July 21, 2015 by Guest

[paulg 0]

I have a UM2, 2 weeks now and after a great 3-4 days of full on and faultless printing, then began to suffer underextrusion as well, and like you, I did the Atomic method clean, but there was no evidence of any buildup. There have been a couple of causes though.  I had one "event" like your last picture where the filament just stopped extruding after a while. Turns out that when the filament retracted (as it does regularly during the print) on one occasion it must have snapped off, rather than pulled back from the head. then it seems to have snagged when it was fed back into the head and didn't actually feed into the print head. The filament didn't grind out at all, but when I pulled it out, it was almost square across the end, and a broken, not melted surface instead of the usual taper.  I doubt that this happens very often!  The square end must have snagged on something as it was being pushed back into the head.

So... make sure your Bowden tube is properly inserted into the head assembly, so that it can't catch on a lip around the print head. Otherwise even with normal retraction, it may get caught up as it feeds back in. Other than that, I think this is a rare event and in my case, I just reloaded the filament and all was good.

The second cause was just not enough filament at times. It gave me almost missing seams on occasion as the layers were put down, and occasionally the top surfaces failed to close over. there were a couple of absolute disasters in there too where the model just came apart while printing.  I increased the extrusion rate to 104% and this has settled things down. I'm not getting the "clicking" from the extruder so with this change I'm not pushing too much filament through.  Some of the other forum threads discuss reducing the print speed at times too, but I haven't had to do this - yet.  A couple of days of intense printing since my last failure, and all is OK for now. Hopefully you can get the same improvement too.

Final thing: make sure the filament isn't snagging on something before it feeds into your UM. It can almost tie itself in knots around the filament spool at times, and your feeder isn't going to be able to pull it off the spool effectively when that happens.  I suspect that's happened to me on a couple of runs - in the middle of the night of course when I wasn't able to see if this was what really happened.

[neotko 1,417]

And you are using cura? That look's like crazy gcode. You could post the first 100 lines of that gcode to check what make's the printer go mad to the endstop, also the speed looks like a G28 code.

[oddoutput 7]

The last problem was with the code yes (no idea why that happend in cura but thank god it was just that).

I tried fastening the bowden tube a bit better and change the rectration a bit.

I made one good print that took 11 hours and after that it went back to what it was.

Everytime the material also just gets stuck in the feeder (because it most likely cant push through), so the material grinds up and it can't retract when changing the material.

I've also had two times today were it was grind up so much that when helping the feed back by pulling it, it just snapped, leaving the rest in the bowden tube.

The teflon part had been drilled up a tiny bit to ensure that the material didn't get stuck on any edge or anything.

[gr5 2,170]

So are you all set? Earlier I gave you a few theories to test out - did you test them? Also I suggested you call Ultimaker - did you? Please let us know what eventually fixed your problem or if you still have the problem and which theories you have ruled out and why. What exactly is the mm^3/sec that you are printing at? (you can see this in cura if you hover over the print speed). the mm^3/sec varies depending on shell width, nozzle width, layer height and print speed.

[oddoutput 7]

I've tried the theories yes (i actually have an ollson block sitting here now, but I don't really want to place it in now if the problem was not the nozzle itself and we haven't found the actual problem yet.

Most prints I did at 1.6mm^3/sec with the standard settings. I've the infill, outer- and inner shell speeds all on 0 now to just use the print speed and for the most recent tries I've put it on 1mm^3/sec.

I've called my dealer and they were going to call ultimaker themselves but I haven't heard anything back so I'm going to call them next week again.

[gr5 2,170]

well a new nozzle can often do wonders - it's worth trying.

[gr5 2,170]

and while you have it apart test the teflon piece by pushing filament through it to test the friction.

[oddoutput 7]

Alright say we're a few weeks further now.

We replaced the teflon coupler and it seemed to have done the job? Till now.

We have also replaced the nozzle with the replacement nozzle, and now with the Ollson block.

two teflon couplers in 500 hours seems a bit quick to me.

The latest thing I tried printing was on 0,5mm^3/sec on 0.04mm layers.

On a side note, are the teflon coupler from 3dSolex longer lasting, because I do think i'll also order an I2K insulator.

Edited August 14, 2015 by Guest