But the filament (PLA) is not comming out of the nozzle.

[ul22 0]

I just startet up my Ultimaker.

But the filament (PLA) is not comming out of the nozzle.

IF it`s comes out, it`s like lumps.

What to do??

[gr5 2,229]

Photo/video please.

With the nozzle still hot, turn off power and pull on the filament through the feeder several cm (please post your country in your settings - if you are UK or USA that would be inches) and then push it back in just to see if it's stuck in the bowden.

What you describe however could simply be that you levelled a little too high and the nozzle is too far from the glass on the bottom layer. Easily fixed by rotating all 3 levelling screws the same amount CCW from below - about 1/4 turn should do it.

[ul22 0]

Photo/video please.  

With the nozzle still hot, turn off power and pull on the filament through the feeder several cm (please post your country in your settings - if you are UK or USA that would be inches) and then push it back in just to see if it's stuck in the bowden.

What you describe however could simply be that you levelled a little too high and the nozzle is too far from the glass on the bottom layer.  Easily fixed by rotating all 3 levelling screws the same amount CCW from below - about 1/4 turn should do it.

 

[gr5 2,229]

Put that part in hot water (tea/coffee temperature) for 30 seconds and then all that gray pla should come out with a toothpick or similar tool.

Please update your settings to indicate what country you are in and if you have the UMO, UMO w/hbk or the most recent model, the UMO+.

[gr5 2,229]

The nozzle you can hold with a wrench and put it in a gas flame and burn all that PLA out. But don't melt the brass. You have several 100C margin between burn temp and brass-melt temp but still - be careful pulling it out of the flame once it starts burning.

Then you can do some cold pulls where you take a length of PLA and stick it into the nozzle while it is hot (but not hot enough to burn) and see if the filament comes out the hole. If not, then let it cool for about 60 seconds - maybe much longer? 100 seconds? or shorter? Until it is almost solid and pull hard to get all the gunk out. It shouldn't come out too easily and should be in the shape of the nozzle. There should be gunk and black stuff on the filament tip. Cut that off and throw away and repeat until the nozzle is clean. This is called "Cold pull" although "warm pull" might be a better name. 90-120C is about the right temp for cold pull.

[ul22 0]

The nozzle you can hold with a wrench and put it in a gas flame and burn all that PLA out.  But don't melt the brass.  You have several 100C margin between burn temp and brass-melt temp but still - be careful pulling it out of the flame once it starts burning.

Then you can do some cold pulls where you take a length of PLA and stick it into the nozzle while it is hot (but not hot enough to burn) and see if the filament comes out the hole.  If not, then let it cool for about 60 seconds - maybe much longer?  100 seconds?  or shorter?  Until it is almost solid and pull hard to get all the gunk out.  It shouldn't come out too easily and should be in the shape of the nozzle.  There should be gunk and black stuff on the filament tip.  Cut that off and throw away and repeat until the nozzle is clean. This is called "Cold pull" although "warm pull" might be a better name.  90-120C is about the right temp for cold pull.

I have followed both your advises. And cleaned the two parts.

I started up printing again - the problem seemed solved.

App. 1/3 of the printing went ok, but then the problem was there again.

[gr5 2,229]

A photo of your part would really help but I think you describe underextrusion - so the problem starts many layers into the print? Not the bottom layer?

I'm going to assume the problem starts not at the bottom layer. I'm going to assume you have underextrusion but without a photo we may be both wasting our time.

There are many things that can cause severe underextrusion. One is excessive retraction on a feeder that is too tight (I think they are all too tight on all shipped UM2's for a long time now). How many retractions do you have? (a photo of your part would help).

Another thing is filament of too great diameter. Measure diameter of your filament. It should be around 2.85mm. 3.0mm is too much.

Another thing is printing too cold or too fast or layers too thick. What is your layer height, print speed and printing temperature?

That's enough to get started but there are about 30 other things that cause underextrusion. Oh hell here's two more: tangles in filament, or dust getting onto the filament.