SOLVED UM2 Nozzle lifetime? or Badly Clogged Nozzle..

[smorgana 0]

Well I've been printing on my UM2 for over 3 years... getting very good prints out of it.

One time in those 3 years the nozzle got clogged.. and I used the atomic method and started working nicely again.

But now I had a lot of trouble with a print.. and it was because it was not extruding enough material.. I got like hairs width material out of it..

So I did the atomic method again and yes... it pulled out some burnt crud.. then it started flowing normally again.

So thinking the cause might be dusty filament... The first print I did after cleaning was to make a dust cleaner...

That print came out great...    The machine sat till the next night... and in my next attempt I was back where I started...   Hardly any material comes out on a material change.. or if I use Move Material...

So I tried the atomic method again.. but in this case I couldn't get any material to flow out the nozzle when I pushed the filament in..  after a few tries I got a fine thread ,but very littl.

When I do the atomic method I never get what I'd call a complete cone shape on the scrap filament.   And it seems as if there is a clog closer to the output end of the nozzle...

So my question is... am I just at the end of life for this nozzle?  Or is there some way I can clear this one..  Am I just doing the atomic method wrong?

Edited November 17, 2017 by Guest

[smorgana 0]

I guess I should have titled this post "Badly clogged nozzle" anyways...

I've done reading on the forum and it's clear from photos that people have posted that I'm not fully implementing the atomic method... People get actual cone shaped pointed material pulled out...

One post though had what might help.. using ABS (I am), they heated up to 260... I've only heated up to 240...

I've also read around and see that the UM2 is not ideal for replacing the nozzle... so I'm thinking about doing an upgrade kit to a UM2 + if I get to the point where I want to replace the nozzle.

[smorgana 0]

Yes. Success. well partly... Just heating to 260 and letting it sit there for 30 seconds, when doing the atomic method got material flowing freely again... I say partly because I still have not gotten a cone shape pulled out...

Anyways I'm back doing a print now and it's looking good.

[geert_2 557]

I did sand a tiny injection needle down to 0.39mm, after cutting off the sharp point. So it just fits into the 0.4mm nozzle. After doing an first atomic pull, I carefully insert that needle from below into the nozzle, to push out any remaining debris in that small opening. And then I do another atomic pull to remove loose debris. In this way the opening keeps its internal diameter of 0.4mm.

Apart from that: I don't really do "atomic pulls" anymore, I rather do "atomic turns": instead of brutally pulling the filament out, I first let it cool down much more, until 25°C. And then I wiggle and try to rotate that piece of filament. Then I heat it up again to 80°C (for PLA), while I gently keep trying to rotate it. As soon as it starts moving, I gently pull. No brutal force, only gently wiggling, turning, pulling. This seems to clean equally well. And yes, I do get the desired nice cone shapes, including a little 0.4mm tip.

Advantage: no risk of damaging the rods or dislocating the nozzle by using brutal force.