Can't get "atomic" method to work in UM2 with ABS

[simonbrouwer 0]

Hi,

Printing with ABS (started out with PLA a long time ago) I regularly have some issues with some under extrusion, and I wanted to see if cleaning the print head would help.

However after several tries with the "atomic" method, still no "cone" comes out.

I heat the printhead to 260 degC, push a cm or so of filament through, let cool to 110 degC, and pull quickly on the filament. Each time I get a more or less straight end, as if the filament simply breaks off from the cone. Maybe there is too much buildup of contamination that adheres strongly to the inside of the nozzle?

I'm wondering what to do next. Dissassembling the print head and try to clean or replace the nozzle?

Best regards

Simon

[DeathMachine 23]

I do a bit of a different method , I repedly pull out filament while cooling .

[neotko 1,417]

If doesn't work at 110, try 115-120-125. Also while cooling down it's good to keep a bit of pressure going down. Also remember to do the atomics (if done without the bowden) with the hotend on a corner so the hotend x/y shafts doesn't suffer/bend.

[geert_2 557]

I also couldn't do an atomic method with ABS+ (=improved ABS with less warping): it always broke off, just like yours. So I had to flush the remaining ABS with PLA first, and then do the atomic method with PLA.

I don't know if this was a problem of that specific ABS+ (which seems to be more flexible than regular ABS), or if it was caused by using lots of PLA first, which might have conditioned the nozzle inside, so that the ABS+ sticks too hard.

If you want to try a much more gentle but equally effective atomic method, have a look at my manual here (second entry):

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

I let the filament cool much longer, and then reheat it, so its inside is more solid. And I replaced the hard pulling by gentle wiggling and rotating. Also, after flushing a bit of filament, I do a "manual retraction" to avoid big blobs of filament getting stuck in the coupler. This gives far less risk of doing damage to the printer or dislocating the teflon coupler than with the normal atomic method. See details and photos in the PDF-manual.

[korneel 176]

i would never do one with PLA or ABS.. use Nylon