Extrusion stopped during print

[spooner777 0]

My second print went very well and on my third one, I tried doing a fan duct. I uses Cura on the fast print setting and it worked very well for 25min but then suddenly nothing came out of the nozzle anymore. The extruder motor kept spinning and I tried to push aswell but nothing came out. What could be the reason for that?

PLA at 230°C also increased to 245°C for a minuite.

[Daid 305]

It could be a bowden plug. It is possible that the tube slides upwards due to pressure and then a plug can form between the PEEK and the tube.

see:

http://wiki.ultimaker.com/images/Bowden_plug.gif

for an graphical explanation.

You need to disassemble the hotend a bit to check if this is really happening.

[spooner777 0]

ok, I removed the tube and there actually was a plug 6mm tall and 6.4 diameter. I removed it and put everything back together. This time I left the tube sticking out by about 1cm and screwed everything back together. I tried printing the part again but it got stuck again halfway through. What can I do to stop this? I also slightly broke the white plastic thing that stops the tube from slipping.

[Daid 305]

If you stick out the tube too far you will compress it which also can cause problems. However, I did this and it has not caused problems yet.

The white clip is essential! If you tube slips then you have a big problem. This is actually one of the biggest problems with the Ultimaker design in it's current form.

Also, make sure that the end of the tube is straight cut. If it sits at an angle on the PEEK then you will have problems.

Owens bowden clamp is often used to fix the tube:

http://www.thingiverse.com/thing:11864

However, you need to be able to print for a while to build it.

I actually have 2 white clips on my tube to keep it from slipping, at the top and bottom. But you need to source extra clips from somewhere then. And you need to modify the top plate.

There are more solutions:

https://groups.google.com/d/topic/ultim ... discussion

https://groups.google.com/d/topic/ultim ... discussion

http://www.thingiverse.com/thing:25867

It's a often discussed problem, if you look around you will find more topics talking about it. With simple and complex solutions.

I recommend to print at 230C or lower, at higher temperature there is more heat going up the tube, which gives a bigger chance for plugs.

[thevoltmaster 12]

 

@Daid So is it possible that my plugging issues are from me extruding at too high a temp? I've thoroughly secured my Bowden tube with the Eclip method and I'm still having extrusion failures. My attempts at troubleshooting has been to increase the temperature. Is there a difference between the types of plug that form so I can see if its a too hot or a too cold problem? Ive tried everywhere from 210-235 with no consistant success.

[spooner777 0]

Thanks for your help Daid! How come you are so active here? Do you work for Ultimaker?

I am printing Owens Fix now. The big main part is almost finished. Hope the rest goes well too.

The Plugs that formed in my peek where both 6.4 in Diameter and 6 in height. You cann see older material on the side and a fresh core from the filament. I print at 230°C. Hope this might help!

[Daid 305]

Thanks for your help Daid! How come you are so active here? Do you work for Ultimaker?

I don't work for Ultimaker. I just like them.

@thevoltmaster: Especially if you do retraction then printing with a too high temperature can plug the extruder.

[spooner777 0]

Tried it with Owens clamp but the flow stopped again. After a few layers it was ok again and then the flow stopped forever. I just opened the nozzle and this time there was no plug.

[Daid 305]

No plug is good, but maybe your extruder is now grinding at the filament. Then tension bolt there could be too tight or weak.

[spooner777 0]

Ok, turned out, that the filament is stuck in the "no friction" bowden pipe. I removed it from the hot end and can pull as hard as I want and don´t get it out.

[Daid 305]

1) Check with UM support if you have on of the bad bowden tubes. There have been a few kits with tubes with narrow sections in them.

2) You can compress the filament with the extruder to an amount that it will no longer fit in the tube. Which was my first major failure. It will take a LOT of force to get this out, and caused a lot of frustration for me. If this is your case, good luck.

[spooner777 0]

Thanks, got it unstuck now, but had to take apart so much stuff. Will take some time to bring it back together. Ill call support tomorrow. Not very hapy with the whole hot extrusion part.

[thevoltmaster 12]

Me too. I feel like im making progress backwards. I've put in my new bowden tube because the old one was defective, and now every time I print I get a plug. Not the kind that moves the bowden tube, but a new one where the plug is the diameter of the tube and then there is a thinner string of plastic behind it. I cant even reliably extrude from printrun, It just keeps jamming. What to do what to do.....

[spooner777 0]

Me too. I feel like im making progress backwards. I've put in my new bowden tube because the old one was defective, and now every time I print I get a plug. Not the kind that moves the bowden tube, but a new one where the plug is the diameter of the tube and then there is a thinner string of plastic behind it. I cant even reliably extrude from printrun, It just keeps jamming. What to do what to do.....

I really hope there is a fix for that. This machine can work so good if it woulf just extrude enough material! And I have no idea what the problem is. To much friction? Extruder screw tension?

[hxorn00b 0]

I was printing the Venus head and it was fine until up to about middle of print then the extrusion stopped. I figured it was a normal blockage and tried to extrude by hand after cutting off the deformed tip of the filament and it was able to extrude. Then I restarted the printing only to have it stop extruding again. Does this sound like a blockage that requires disassembly of the hot end? I am hesitant to do the disassembly. Also how to prevent the extrusion from stopping in the middle of a long print? Is there a way to restart where it stopped? Thanks for help in advance.

[rewolff 0]

In my experience when my extrusion stops midway during a print, and you can push filament out by hand, there are two options. Or maybe both.

* First the screw on the material feed may need adjustment. Too tight or too weak and the material slips.

* Second: the actual extrusion might be requiring too much force. This could be because you're trying to go too fast, or you might be running it not hot enough.

[spooner777 0]

Dissasembling the hot end is not to bad. All I ever had to do was to unplug the bowden from the peek insulator. The hot end can stay screwed together. Did this 10 times in 2 days.

[medveybo 0]

Hi guys, I have been reading the forums for answers for a week now. We assembled our Ultimaker machine last week and I have been trying to find the right configuration for black PLA, but I haven´t been able to produce one decent print. The problem usually was that extraction stopped during prints. I tried everything I could find on the forums concerning this matter (including changing the pressure at material feed end, finding the right temperature and today I had my first plug that I removed after dismounting hot end).

So far I could solve most of these problems with the help of the forum, but the mysterious change of extraction rates didn´t stop and is still without any explanation. Today I almost had a perfect print, but just before reaching the last 5-10 layers the printer stopped extruding again. Right after the print I tried extruding by hand, which seemed to work - for a short while. After that it stopped and has never restarted since. Practically nothing comes out of the nozzle, even after dismounting, cleaning every piece and assembling again. With unused PLA there seems to be no friction in the bowden tube, so I assume the source of the problem is not there.

I even tried heating up the nozzle without the PEEK on, but nothing came out of the nozzle. I made an attempt to clean it from the other end and letting it drip out that way, but that didn´t help either. Although one curious thing happened: melted PLA was coming up from between the heater and the brass tube. (see picture) Anyone experienced this before?

I´m starting to think that the nozzle got blocked from the inside. What can I do? I would be grateful for any suggestions as to the next steps as well as for the reason of the previous extrusion stops.

[Daid 305]

Maybe some kind of dirt or something is blocking the nozzle tip. You could try heating it up and then using compressed air or something to blow from the tip side?

[spooner777 0]

Quick update:

Just got my new tube. The size difference is BIG! I made a picture will upload later. Now it extrudes nice thick layers of pla. Fingers crossed this print will work!

It worked!

[rewolff 0]

We've been trying to clean out the the clogging of the nozzle by pushing small electric wires up the nozzle.

[medveybo 0]

Thanks for the tips, I could clean the heated tip with a really thin wire. So the total blockage has been solved. I almost had my first print without a problem, but extrusion stopped again on the last 10 layers. After unsuccessfully trying to print again, some extrusion by hand and trimming the hot end of the material extrusion was normal again. I just started the project again, we will see what happens.

I'm beginning to suspect, that it is actually the heat creeping up the bowden tube, melting the material which in turn gets thicker and thicker at the end, and eventually the extruder motor cannot cope with the situation. This sounds reasonable, because the problem is usually solved by trimming the hot end of the material. Although should this happen with 220 degrees and one hour long prints? I would've guessed this problem occurs at higher temperatures and longer prints.

[medveybo 0]

Okay, so extrusion stopped much faster on the second run. I tried lowering the temperature to 190: extrusion was very diverse, sometimes normal sometimes really low without me touching it. It never fully stopped though as before, but I eventually aborted the print, because it would've been useless.

I'm getting really tired of having a problem, reading the forum and feeling like 'oh now I understand what is happening', I go and fix it and the same thing happens again and I have to face it, that I DON'T understand what is happening.

Does anyone have any idea of why extrusion might be failing like this? Or even what symptoms I should look for to get closer to identifying the problem?

[Daid 305]

190C is a very low temperature to extrude at. You're much better off at 220-230C. I'm doing 8 hour prints at 230C just fine.

Are you sue you're not getting this kind of plug:

[medveybo 0]

I'm pretty sure the problem is not the bowden plug. I have written it before, but I can get the extrusion back on track simply by pulling out the filament and trimming the deformed hot end. After that, when I push it back extrusion is suddenly good again. If it was a bowden plug I suppose it would need a bigger effort to fix. I sometimes do this even during print, because if I notice the problem right away, then I can do the correction before it finishes the layer and it doesn't make much difference. But of course I cannot sit and watch over the printer every time...

Anyways this problem has been quite unpredictable so far, and yesterday we did a 4 hour print, which was almost "perfect" but once again the top layers weren't printed because of extrusion failure.