5

For PLA I would recommend Tetrahydrofuran, it will clean your nozzle for any left overs. But you might also want to check the health of your isolator coupler (the white part next to the brass tube).

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6

Can you check the thermistor? It might be not working in a good way.

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7

We have also had similar problems. One solution is to repeat the atomic test until you get a smooth clean result. Also use a filament of another color in order to see the residue that you are removing. We have made a fine metal tool with 0.5mm diameter and made a very sharp tip. We heat up the nozzle to 260 and plunge the tool into the nozzle and work it slowly around the edges of the hot-end. I will send you a picture of our tool later. This should be done with caution in order not to damage the inner tube of the hot-end. You can also check the Ultimaker forum. 3D printing forums - Ultimaker Community of 3D Printing Experts

Kind regards,

Jaime Cavazos

Ultimaker reseller Greece

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8

Hi Baloe3D, thanks for your feedback. The nozzle is super clean, in any case, I’ll consider Tetrahydrofuran for the future.
To check the isolator, should I disassemble the hotend from the printer?

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9

Hi Jaime_1,

Thanks for your answer, I’ll take a look at the ultimaker forum immediately and, if I can’t find anything I’ll make a similar post there. I look forward to seeing the picture of your tool, so I’ll try to repeat the procedure with my Ultimaker.

10

Hey Idamartha,

I don’t have a thermometer in the lab so, honestly, I can’t be completely sure that the temperature is exactly correct. But both PLA and ABS are melting at the right temperature, so I can suppose that the thermistor is fine

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Hey Alvinlab,

I’ll try within today and I’ll let you know!

12

I’ve had similar problems where the thermistor said it was 30 degrees warmer than it actually was. I verified this with an infrared heat sensor. New thermistor solved my problem, probably was a faulty cable.

13

Ok, I’ll try to buy one during the weekend. In any case, it’s a good tool to have in the lab

14

I don’t have experience with UM2, but it makes sense to remove the hot end to reach the isolator coupler. I have UM1 which should be about the same.

15

After you do all the easy checks…like making sure there are no stringy bits binding the filament in the bowden tube, and after checking and maybe cleaning the extruder gear, and trying a different nozzle…I would think that it is likely to be the teflon coupler that needs replacing. They are a consumable item and I have been through a couple.

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16

Try to put a litlle bit of WD-40 inside the bowden tube, it as solved my extrusion problem with the Ultimaker 2GO.

Regards

Marc

17

infrared thermometers will not give you an accurate reading. you need a thermistor to check temps.

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18

Had same issue, replaced the teflon coupler. That was causing this issue and the problem was solved!
This is wat you need → http://3dsolex.com/teflon-replacements

I replaced it with this one, and the printer prints like a charm :slight_smile:

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19

Thanks for your suggestion, I’m quite sure that the Teflon coupler is the problem: I checked everything else and my idea it’s confirmed also by the position of the issue highlighted by the Atomic Test.

20

Feeder is fine. I’d say that’s the Teflon tube at this point

21

Agree with Brammezz as I encoutered that before, and solved by replacing a new telforn. Good Luck!

22

I have been fighting on and off extrusion issues with my two Ultimaker 2’s for a while and this thread may have pointed me to a solution that I had not thought of nor tried. Historically I do a lot of atomic cleans, I have replaced teflon couplers, I keep the extruder gears clean, and prior to my upgrade of both my printers to “+” versions I had replaced the Bowden Tubes with “slippier” versions.

What I had not done was use something like the below to clean, and more importantly, lubricate, my bowden tubes:

http://www.thingiverse.com/thing:190118

The difference has been profound. The same print that had extrusion issues printed perfectly with no changes other than adding this filter. I am not sure why I had not done this until now, or in fact if there is some reason that I should not be using it…?

Wow though. Thanks Marc!

Will

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23

That’s a cool suggestion, I’ll try to print one of them and use it :slight_smile:

Cheers,

Federico

24

I’ve seen this issue before when the nozzle seems to be clean, I’m wondering what your PTFE coupler looks like and if it might be worn out? I change mine about every 4-500 hours but it depends what temps you normally work at. It’s a good suggestion below with poking something into the nozzle. I use a 28 gauge needle (0.36mm), and you can find them any medical supply store. I would also look at the gear box in the back. Sometimes when small bits of plastic accumulating in it can slow the forward movement thus causing underextrusion.

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