Ultimaker 3 - Printhead full of filament

[PAMB 0]

Hello,

unfortunately, for the third time I have had the following problem with the Ultimaker 3 at my institute: the nozzle jams during printing and the print head gets stuck on the buildingplate. As a result, the UM3 keeps printing and "blows up" its own case (see the picture below). This error occurs with different materials (PLA, HIPS) and with different sized printing models. After that the printer was always sent in and repaired, the last time a completely new print head was installed.

My question is if someone knows the reason for this error or how to avoid it. The failure of the printer is always very annoying. I would be very happy about your help.

 

Apparently nyrociel had the same problem

 

[gr5 2,167]

This is common enough that it has a name:  "head flood".  It's never happened to me but is common on the list.

 

There are 2 possible causes.  One not as likely:

1) The door doesn't stay closed and pops open because things are crooked.  You can usually adjust the magnets a bit or loosen two of the screws that hold the door together and adjust it so it stays closed better.  This is the unlikely cause.  Very unlikely.

2) The much more likely cause is that your part comes loose from the print bed when the part is wider than tall.  If the part is taller than wide it just falls over and you get spaghetti on top.  If it is wider than tall then it gets dragged around the print bed like a hokey puck on ice and you get filament going into one spot of the part and it backs up inside the head.

 

#2 is especially likely since I see you are desperate enough to try blue tape. 

 

Blue tape only works if you clean it with isopropyl alcohol to remove the waxy surface that keeps the tape from sticking to itself.

 

Anyway, getting parts to stick to the bed better is a simple but long topic.  There are many things to learn.  Once you learn all the key points you WILL NEVER HAVE A PART COME LOOSE AGAIN.  Ever.  In fact you will have to *not* do some of the key techniques as you will be frustrated by how well the parts stick.  I demonstrate lifting the entire printer up with a tiny print stuck to the bed.  Anyway, my video is long but thorough.  At the time I tried to keep it short and even went through cutting out a second here and there to make it shorter.  I could do a lot better but it's a lot of content to get through.  It's worth it.  It will save you many hours of frustration.  I explain not just what to do, but why.

 

[PAMB 0]

Thanks for the answer! I'll watch the video today. Hopefully it won't happen again 🙂

[danielkrice 4]

Fitting this gives me a bit more peace of mind with longer prints.

 

https://www.thingiverse.com/thing:4091030

[Digibike 107]

2 hours ago, danielkrice said:

Fitting this gives me a bit more peace of mind with longer prints.

 

https://www.thingiverse.com/thing:4091030

Not really. You will online crash more, if this problem happens... The printed object lost his adhession to the headbed. So it will began his journey with the nozzle... Your nozzle is blocked and so the filament will only can out up in the core. If the fan will open, you can rescue the cores and the fan will saved. The next is,  that if the fan is open, the core will not cooled.  So the temperature goes in the upper zone. The filament will be to hot in the coolzone- the Extruder begins to clogging and no more filament can be to the nozzle.  With This tool, you can thinking, at which time the print will stopped, if this problem will happens.... you must correct your adhession problem, but if you want to eliminate the adhession problems with this, I think, you get very fast greater and much expensive problems. There is a reason, why Ultimaker had a magnetic look and not a cheap plastic click look... sorry about my bad english,  but I hope,  you understand,  what I mean...

 

Digibike

Edited August 10, 2020 by Digibike

[danielkrice 4]

Not sure I follow your comment but I’m happy with the part and haven’t had any disasters or ‘head flood’ moments since, even with print adhesion fails.

 

Each to their own

[Enigma_M4 119]

On 8/10/2020 at 11:26 PM, danielkrice said:

Not sure I follow your comment but I’m happy with the part and haven’t had any disasters or ‘head flood’ moments since, even with print adhesion fails.

 

Each to their own

 

Using a clamp or not, I think the most important is proper working of the magnets, that hold the fan bracket close.

If that's not the case, there's a good instruction video, provided by @fbrc8-erin:

 

However it is achieved: preventing a head flood is preventing lots of frustration.

Regards

[Adam_UL 0]

If a head flood gets so bad that your print cores wires become dislodged. (the wires that are wrapped in a white fabric at the back of the heating element).

How do you remove the print core?

[Digibike 107]

I mean´s with this, your Print will not lost the adhession from the headbed because the open Fan bracket. But if the fan bracket is blocked, you to baken your Cores and break your Fan with filament. The magnetic backet is a safety. If this happend with your object and the nozzle will blocked with the Object, at a time the fan bracket will open because of the filament which comes and comes and can not go down to headbed or object. And, if this will happend, the cores becomes no cooling. The core will hotter and hotter in the cold zone - and go into clogging. With this part, if your object will lost the Adhession, your fan bracket has no chance to open and stop so the Extrusion at any way... That is the only, i want to warn for...

 

with regards,

 

Digibike

[Adam_UL 0]

So this shows the aftermath of my "head flood" , in removing the flooded plastic the wires were ripped out of the print core. This meant the printer no longer recognised that the print core was there. And now I don't know how I can remove it (the Print core)?

Edited August 15, 2020 by Adam_UL

[Digibike 107]

Hi,

It seems very terrible...! I only had it 2 times. I used a heat gun for this. Set this to 280 degrees and let it blow from the back to the front at an angle and repeatedly pull it off with a spatula and a flat-bladed screwdriver and scrape it off the spatula (it's very hot ... !!!). I have to say, I have a UM3 Extended - I can put the hair dryer on the heating bed and my hands are free. First, remove the housing of the printhead as best you can - the fan and soldered connections don't really like temperatures above 200 degrees ...
With a bit of patience it was possible - even the cores were preserved and still work today - at least 2 years ago ...
Was your flap blocked because it even sheared the cables?
The parts that you remove from the printhead are best fixed on the back with a cable tie or something similar. And blow forwards and work from front to back (so heat up the front and wipe off and when the front is "clean", continue working towards the rear, so push the hair dryer backwards ...). It gets tricky, the core's then out of the
To get guidance. Core 2 in particular will cause problems. This makes vertical movements with and the smallest blockages in the rail lead to blockage. Caution and patience are required, but it works!

 

Good luck, Digibike

[Adam_UL 0]

Hi Digibike,
All this is very useful in hindsight, but what I want to know is how I can remove the print core now that the plastic is gone, the electrical connection between the core and the printer has now gone, there is a chance that I can reconnect the wires once it's out but not while it is in the printer. 
Does anyone know how to manually remove a print core, when the printer does not recognise that it is there?
Usually when you remove a print core you go through the printer's maintenance menu on the lcd screen/scroll wheel interface on the front of the printer and tell the printer to release the print core. How can you by-pass this step when the print core is no longer recognised by the printer?
Cheers

Adam

[Enigma_M4 119]

Hi Adam,

you can remove the print core while the printer is powered off and unplugged, without using the menu, if the filament is unloaded.

Just open the fan bracket, compress the print core lever and pull out the print core to the front, just applying a little bit of pressure on the upper corner of the translucent part of the print core lever.

If it's the right-sided print core, it must be in the lower position.

Regards

[Adam_UL 0]

awesome, cheers. I'll give that a go.

[Adam_UL 0]

So I got it out! but the reason it was stuck was quite unfortunate. It looks like that the flood was so bad that the unwanted plastic collected above the heating element and prevented the spring release mechanism from working. If the wires to the heat element were still connected, it might have been possible to melt away some of this plastic.

My advice if you suspect this has happened to you is to accept that your print core is busted and remove sections of it with pliers being careful not to damage the rest of the printer. Then buy a replacement core.

In most other circumstances the heat gun approach would work, but in this case it risked melting other parts of the printer which would end up costing you more than just a new print core.

[Digibike 107]

That is what I meant by blocking the flap, since nothing prevents the extrusion, it must inevitably block the fan at the front and "flood" the receptacle at the bottom. Where else should the liquid plastic go ...? When it opens the flap, the plastic pushes the flap open over time, the cooling thus fails and the heat slowly rises in the core. This means that the material is liquefied very soon before the transition zone and can no longer be pressed down. The conveyor pinions begin to slide over the filament (so-called clogging begins). With blockade, this only happens when the fan is blocked - like electric motors a lot ... and the hot end part of the core is completely cast. So I'm not that excited about this bracket. If you want to do something like that, as an additional backup, I would make the bracket in 2 parts. And the flap end with metal plates and the U around the print head with a magnet. So I have the same effect - with the difference that the flap can still be pushed open when pressure is applied (the predetermined breaking point remains, so to speak).
I've already come up with a solution that should kill the problem: Attach a brass brush to the back, to the right of the stepper and to the left of the first guide, which protrudes slightly into the printing area. Let the print head pass each layer briefly - from the 3rd layer onwards, it is enough. What's the point The nozzle is cleaned on the outside and if parts stick to it, it rubs off the brush. The print is over, but not the printer "messed up" ...

 

Digibike

[Adam_UL 0]

Do you have a photo? it's quite hard to follow your description.

[Digibike 107]

A Picture explain better than thousand words... I know... And if the english is too bad like my english - it will help much more...

I have no photo. I had this problem 2 Times, last about 2 Years ago, I think so, so it will take much more time from other projects without right benefit... 😉

But I had made a quick and dirty picture to show, what I mean. The Ultimaker headbed only makes Z-moves. Your Printheads make X and Y moves.

If you take brass brush, cut the lower brushes - it will only clean the headbed - not really a good Idea... and let the upper brushes and attach this on the back of your Printroom, you have a "clean area". If the Printhead will drive through this area, the nozzle will collide with the brushes. The only one, what you must do, is to say you slicer, go to this area and set flow to zero and go along, than go to next layer. It´´s a simple method...

If you look in your Printroom of the Ultimaker, you see - sorry for this simplify drawing - in front the headbed and left upper the Stepper. The Orange ist now the Brass brush, I mean. You see, it takes a short Part inside the Headbed - the reason, why you cut the lower brushes... If the Printhead drives in this Area, all will collide with the brushes and will stripped of from the nozzle...

I hope, you understand, what I mean... I can not really good explain and in english it will not be better... The reason, why I´m most time in german threads... 😉

 

Digibike