Feeder motor skipping, nozzle clogging - after a while working everything repeats

[iikkuli 1]

Hello all the wise,

My problem with Ultimaker 2 is the feeder motor skipping and nozzle clogging. I'm not entirely sure if nozzle is clogged because of motor skipping or vice versa.

Anyway: once i get the material flowing from the nozzle I do Atomic method. Sometimes I do get it out correctly and sometimes the filament breaks. If material flow is good then I have continued without successfully pulling out cone shaped filament (as described in Atomic method). After this I can make a few successful prints but after that the nozzle starts to clog again; though the feeder motor is skipping every once in a while when inserting material and trying to begin a new print after cleaning the nozzle.

I've gone through various topics around this here on this forum but nothing has helped so far.

I have tried these:

- Cleaning the nozzle with Atomic method (sometimes though my filament breaks and doesn't come off correctly)

- Changing the nozzle and teflon part (also the spring) few weeks ago

- Sticking some wire inside the nozzle from below when nozzle is hot (this helps when it is jammed and no material comes out when manually feeding filament to nozzle like in Atomic method)

- Disassembled the feeder and removing all the plastic particles inside and from knurled shaft

We use ABS and PLA (several users) and we haven't done a proper clean up (like Atomic) after material change. We use Ultimakers 2,85 PLA and for a while we've had eSun's 3 mm ABS filament (2,9 mm±0,05). After changing nozzle and teflon only a few parts have been printed successfully before the problems started again. Overall we have printed some 700 hours with no problems and hence we thought the problems were caused by the teflon part.

Is it possible that bowden tube could be worn from inside and cause too much friction?

Anyone there to offer some more tips and tricks?

[DidierKlein 729]

Filament diameter is probably the cause here. Esun is 3mm and is too wide. So probably your problems come from that.

Make sure your atomic pulls come out clean especially if you go from PLA to ABS and back and forth

[iikkuli 1]

Filament diameter is probably the cause here. Esun is 3mm and is too wide. So probably your problems come from that.

Make sure your atomic pulls come out clean especially if you go from PLA to ABS and back and forth

 

I thought so too but the problem exists also with Ultimakers PLA :/

Also we have completed many prints lasting 20-30 hours with eSuns ABS filament.

Edited August 10, 2015 by Guest
Added comment about eSun filament

[DidierKlein 729]

Then it must be the nozzle that is partially clogged.

If the feeder is skipping it's because the filament has some friction somewhere.

If the teflon is new then it probably comes from the nozzle. You want a clean cone shaped tip when doing atomic pulls

[iikkuli 1]

I will try my best (again) to achieve this. Any tips for how to get the filament out correctly? Mine breaks very often.. I've been trying to hold some pressure while nozzle cools down but no luck so far.

[DidierKlein 729]

I just finished a tutorial on my website if you want.

You want to pull quickly and firmly, if it's too hard then you need to increase the temp slightly, if it's too soft you are either pulling to slowly or too hot

[iikkuli 1]

Looks like I hadn't done enough of Atomic method to clean the whole nozzle. So far it seems to be working, I have a test print printing right now. I'll report if I have any more issues but I believe this may have solved it. Thanks DidierKlein!

[iikkuli 1]

One question occurred my mind: Does it matter do I use PLA or ABS for nozzle cleaning regardless of what I have been printing with? I changed from blue ABS today to white ABS and decided to do Atomic method in between. However maybe my chinese ABS so rubbish that it just breaks and doesn't come off at all cone shaped. Then I used my Ultimaker PLA and it worked like a charm.

Any thoughts?

[DidierKlein 729]

In theory PLA should work to extract ABS residues. Just make sure your hot temp is high enough to melt ABS.

And regarding cheap chinese ABS i would not recommend printing with that, you will most certainly run into problems. Quality filament will eliminate a lot of problems (it's my opinion)

[iikkuli 1]

Okay, that is what I thought also; shouldn't have problems on nozzle cleaning.

Many thanks!