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0.25mm nozzle problems  

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Alkazander
(@alkazander)
Active Member
0.25mm nozzle problems

Hi guys,

Been experimenting with changing nozzles, down to 0.25 and up to 0.8.

No problems with either the first time but after a number for prints with 0.8 and 0.4 nozzles I wanted to use the 0.25 again.

(Its actually an 0.2mm from Prima)

Now I cant get the print to run all the way, 1st layer test looks great and so, even printed an 50x100mm which looks great.

But after about half way the extruder starts to click, it get worse then its clogged.

After unloading/loading it work again.

Checked speed setting for the filament and got some success with parts that a just 5mm high but anything higher it bugs out.

Then I tried changing from PLA to PETG (black print is the PLA and the white PETG) but no use stops at about the same place.

What to do?

Posted : 13/08/2023 8:17 am
Patrick McNamara
(@patrick-mcnamara)
Estimable Member
RE: 0.25mm nozzle problems

I had significant issues printing with a 0.25mm nozzle until I switched from a Prusa heat break to an E3d heat break.  The difference is small, but seemingly significant when printing with small nozzles.

See this post for the difference:  https://forum.prusa3d.com/forum/postid/139107/

My theory is the the slower volumetric flow, with a small nozzle, allows the filament to soften further up, eventually beyond the small step.  Lots of retractions makes it worse.  Eventually the filament softens enough and expands above the step and jams the nozzle.  The nozzle itself isn't plugged.  You can pull the filament out, trim the end, feed it back and have it properly extrude.  Lots of times, you don't even have to pull the filament and trim the tip, just retracting is several millimeters is sufficient.

Large scale 0.25mm printing is certainly possible.

Posted : 13/08/2023 2:03 pm
Alkazander
(@alkazander)
Active Member
Topic starter answered:
RE: 0.25mm nozzle problems

Thanks Patric for the info.

With your description I can make sense of whats happening, with the PLA I got sputtering after a while if I didnt keep the temp up, now I know why!

 

/Alx

Posted : 14/08/2023 6:41 am
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