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Real bad chewed filament - Girl needs help!

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Hi everybody! I need urgent heeeeeeeelp!

I got my UM2 last week and up to this morning I had no problems.

The grinding (chewing) started today after printing to top of my piece that has many small holes. That print came out real bad as if missing material.

I just realised what happenned when started my next print as no material would be released.

I am using the blue PLA that came with the machine and put the pressure of the feeder to the lowest position but it still grind the material all along the printing.

I found out that the filament was completly chewed and would not move up or down not even when using the "change material routine".

I had to cut the material, heat the nooze and take it out. Also I had to disassemble the entire feeder to be able to take the filament out. (check pictures)

The thing is that I allready had to do it 3 times today and before every new print the same happens. Until I dont disassemble, cut, clean and assemble all again there is no deal.

Please help this girl here!!!

 

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Yes, tell us nozzle temp and print speed and layer height.

What is the air temperature in sao paolo? If over 25C that might be part of the problem. Especially after 30 to 60 minutes of printing. The feeder motor gets warm enough to soften the PLA in the feeder. That is *one* possible problem. One solution might be to remove the back left cover (only 2 screws - very easy) and put a table fan blowing on that corner of the printer to keep the extruder motor 10C cooler.

Is this a part with lots of retractions? Usually there is a retraction when on a given layer the print head moves from one "island" to another. For example printing the branches of a tree - lots of islands. Printing a head - very few retractions.

 

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The pressure on the filament in the feeder should not be on the lowest point possible! Put some pressure on it so the feeder can get a grip on the filament. If it doesn't have enough grip the turning part of the feeder will just scratch over the filament without getting enough grip to pull it into the bowden tube and therefore grinds it down.

If grinding happens again you don't have to disassemble the entire feeder!

Try "change material" and then pull the filament down and out when the feeder motor starts turning. If that doesn't work you can push down the white clamp-thing that connects the bowden tube to the print head and pull out the tube, then heat up the nozzle and pull out the filament. Thats way easier than disassembling the whole feeder.

 

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Hi guys, thank you for the answers.

How can I load pictures? You need to see how bad it looks like.

I noticed that the real bad chewing happens in the end of any print (big or small running prints).

The back fun is working when I turn on the machine.

I am using 215 as nozzle temperature, speed normally 70% only and layer height 0.1mm

Last week we had high temperatures in São Paulo (34) but yesterday and today we are having maximum 24 Celsius.

At the end of every print I have to unlock all the nozzle screws, take the filament off, cut and I check the motor temperature. It is hot but I can still touch it to help screw all back together.

But the heating of the motor being high and softening the material before chewing might make sense.

I changed the machine location as maybe there was not enought cooling air in the back but the problem persists.

I can not take the filament out without disassembling all. It chews really bad. The motor runs and runs but even pulling hard it wont come out by trying the "change material" routine.

To have the lowest tension on the filament I have to keep the white indicator at the lowest position, right?

 

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Hi gr5

 

Yes, tell us nozzle temp and print speed and layer height.

What is the air temperature in sao paolo? If over 25C that might be part of the problem. Especially after 30 to 60 minutes of printing. The feeder motor gets warm enough to soften the PLA in the feeder. That is *one* possible problem. One solution might be to remove the back left cover (only 2 screws - very easy) and put a table fan blowing on that corner of the printer to keep the extruder motor 10C cooler.

Is this a part with lots of retractions? Usually there is a retraction when on a given layer the print head moves from one "island" to another. For example printing the branches of a tree - lots of islands. Printing a head - very few retractions.

 

The problem started when I was printing a small area with a lot of retractions indeed. But why it persists?

By back left cover, do you mean the internal metal cover of the motor?

 

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White indicator at TOP is lowest tension. I've never touched mine. Ultimaker changed to a weaker spring a while ago and everyone disagrees on if grinding is caused by too strong or too weak spring pressure or not related. It's certainly something to try.

232734e1252t47x6b4gp44.jpg

 

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[...]

To have the lowest tension on the filament I have to keep the white indicator at the lowest position, right?

 

No! You have the lowest pressure on the filament when the indicator is at the highest point.

The feeder looks like this from the inside:

gallery_67_479_245139.jpg

The white indicator is on the left. If you screw it down you higher the pressure on the filament. Keep it in the highest position for the lowest pressure.

 

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By back left cover, do you mean the internal metal cover of the motor?

 

The big white metal cover, yes. You don't need it. It's just to look pretty.

 

I am using 215 as nozzle temperature, speed normally 70% only and layer height 0.1mm

 

That's probably fine but I realize now that you probably use "quick print" mode. Go to "expert" and "switch to full settings..." and start with 50mm/sec for a "medium" speed. And then you can leave speed at 100%.

 

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tube end srinkerd

tube end srinkerd 2

filament weld in the tube

filament weld in the tube 2

Hi guys,

I think my motor is heating too much.

Today I tryes to print but nothing came out.

I found out that the tube end in feeder motor srinked and the schewed filament welded to the internal wall of the tube.

The motor is heating only by letting the machine on and every atemp of loading material ends the same. Real bad scewed filament.

Could it be a motor problem? Could it be a mechanical problem? I started using it last Thusday night.

The motor is damm hot but I can still touch it.

Anyone has ever had this problem before?

What can I do?

 

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on the filament just above the grinded area you also see where the remains stack up. This may also

be a problem in your bowden tube, when at some point it does decide to get a grip and continue to feed.

Whether by manual push or all by it self.

What is the tube you are holding?

The bowden tube?

If you cut off so much, you probably need a new one..

If I imagine it correctly, instead of disassembling the entire feeder, remove just the bowden tube from the feeder by removing the horse shoe, push in the white tube holder/tightner and pull out the bowden tube.

It is much easier and faster.

 

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What is the tube you are holding?

The bowden tube?

If you cut off so much, you probably need a new one..

If I imagine it correctly, instead of disassembling the entire feeder, remove just the bowden tube from the feeder by removing the horse shoe, push in the white tube holder/tightner and pull out the bowden tube.

It is much easier and faster.

 

It is the bowden tube. The material welded to it, I had to cut. I instaled back but I did not start the machine yet to test.

The reason I think it is a motor problem is that you can see that the material is melting more and more inside the tube and closest to the feeder. So it is melting and at a certain point it rotates in fake (I dont know if this expresion exists in English), but it rotates without moving the filament as it is destroyed at this area.

I am going to try to release the filament without disassembling the feeder but it does not solve my problem.

As soon as the machine is on again after 20 minutes it is going to heat up all again the the same repetes.

Is this a machine problem that can be solved by us or do I need help from the factory?

 

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If you cut off so much, you probably need a new one..

 

Yes. Tell Sander you need a new one now as it will take days to receive it. Weeks maybe. But you can print fine towards the middle and back of the printer (but might be too far towards the front maybe).

As an experiment - so you understand how suddenly PLA changes around 60C, boil some water and pour the hot water into a mug or glass. Already the water should be cooled to 80C. Now take a piece of filament and stick it in the water for 10 seconds and pull it out and bend it. Blow on the filament for 3 seconds and continue bending until it cools and suddenly it changes back to normal.

Your fingers can handle much higher heat than it takes to soften PLA.

A small fan should be able to keep the stepper motor a little bit cooler - just enough for the PLA to stay strong.

Or you can lower the current to the feeder motor. It's easy to do but I don't recommend it as it is good to have the full power of the feeder.

I'm still not convinced you have a "heat" problem. But if putting a fan blowing on the stepper helps (blowing from the front) then that would prove that you *do* have a heat problem and we can work on other solutions. Also set your heated bed to 50C (no hotter) if you are blowing air across it to the feeder stepper. You can do this on the TUNE menu after you start the print.

It's still possible that you had a jam in the bowden tube and this caused the grinding. Or it's possible the grinding caused the jam/melt in the bowden tube.

 

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Okay - I think it is time to lower the stepper motor current after all. From cura right-click on the "Save" or "Floppy disk" or "Memory Card" icon and choose "save gcode...". Save on your computer somewhere and open this with text editor (on Windows use Notepad by dragging it onto notepad). Add the line of code as shown in red. By default the current for the extruder axis "E" is 1250 milliamps. Try 1000 or 1100 milliamps. You shouldn't need to go below 1000 milliamps (1 amp). 1000ma might be too small and your motor might skip a lot. It is safe for the motor - it will not hurt the printer. But your print might have missing plastic (small holes). If so try printing a little hotter, 230C (you should try this anyway) and a little slower:

;FLAVOR:UltiGCode

;TIME:1357

;MATERIAL:3109

;MATERIAL2:0

;Layer count: 74

;LAYER:0

M107

G0 F9000 X104.050 Y101.947 Z0.300

M907 E1000 ; set current to 1000ma - THIS LINE WAS ADDED

;TYPE:SKIRT

G1 F1200 X105.507 Y100.634 E0.23536

G1 X105.707 Y100.469 E0.26647

 

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It is the bowden tube. The material welded to it, I had to cut. I instaled back but I did not start the machine yet to test.

 

Next time maybe remove the tube at both ends (remove clips, push down on collar to remove) and don't forget which end is which! The end on the feeder has been drilled out a little wider. Of course you threw that part away!

Then push out the bad piece with good filament and if it is melted/welded try dipping in hot water first for 30-60 seconds.

 

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I put the bowden tube back in place and it fits ok but I did not turn the machine on yet.

Am I really going to have problems just because it 50mm shorter?

Which material is it made from? I can try to source it locally.

If I have to put the fan blowing from the front of the machine, would it not interfeer on my printing temperature as it is going to blow in the nozzer?

I am going to try to take the filament out without disassembling the feeder. I just need to get hold of a tool to force the bearing away. I have to ask the neighboor. Girls dont have tools laying around like that but if you ask for shoes... ahahahaha

Could a jam in the bowden tool cause a motor heating?

I am going to let the machine on for 20 minutes or so and check again the temperature.

Thanks

 

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Next time maybe remove the tube at both ends (remove clips, push down on collar to remove) and don't forget which end is which! The end on the feeder has been drilled out a little wider. Of course you threw that part away!

Then push out the bad piece with good filament and if it is melted/welded try dipping in hot water first for 30-60 seconds.

 

Hi gr5,

the part I cut was not the nozzle end but the feeder end.

That is where it got welded.

And I did had to remove the horse shoes from both ends and unlock the bowlden tube. I heat the nozzle and took it out of that end after that as I could not pull from the feeder end pull it out from the other end.

Next time before cutting I am going to try to warm it up first.

Should I try the fan of to lower the amper first?

 

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Could a jam in the bowden tool cause a motor heating?

 

Maybe a small amount. Stepper motors are very strange and use the same amount of current whether they are working hard or just resting but the voltage can change. This means it *might* get hotter when working harder but they are quite hot even when resting!

 

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Should I try the fan of to lower the amper first?

 

:-P

Both I think. If things are better then try just one. You don't need a strong fan but it needs to be aimed to the motor. The nozzle should be okay - it will automatically adjust within a minute to the new wind. So turn the fan on before you start printing to let the nozzle adjust.

 

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Did you mention if the 3rd fan on your hotend was running? That one being off will cause heat to creep up from the hotend into your bowden tube causing the filament to expand like you're experiencing.

There should be a fan on the hotend that turns on the moment you turn your machine on.

 

Yes, this fan is working.

I turned the machine on and left it for 30 minutes and the feeder motor did not get hot.

I printed a 25 minutes test (with a little fan aimed at the feeder motor) and the motor got a bit hot by the end of the print but did not chew the filament.

Now I am on a 3:45 minutes print and I still have the mini fan.

Lets see...

By the way the shortenned bowden (I cut 50mm) did not give me any hard time but until I get a new one I am going to let all prints to the back of the table so it wont have any streching to do. The only difference I noticed is that more left over material leaves the nozzle before printing and I dont know if it has anything to do with the shortenned bowden.

I am back after this print. After 15 minutes the motor temperature is allready getting started.

 

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Keep in mind that those servos are very tough. I think they can get up to 80C no problem, no damage. It's the filament that has trouble.

You can of course print with ABS which can get up to 100C before it gets soft but ABS is more difficult to work with in general than PLA. Different brands of PLA have a small difference in glass temperature. You are using "UM" light blue filament I think. I have never had trouble but it's one of the worst filaments UM sells. It is a good filament but the other colors tend to be better. I don't know why. But I love my "UM light blue". It's my favorite color I think for showing off really detailed prints. I have never had your trouble but I also have air conditioning and the room never gets above 23C.

 

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