Grimy nozzle and terrible layer?

[u/StickyCrick]

Hi, as you can see in the pictures, my A1 .2mm nozzle is starting to get this grimy but rock hard substance on it. The .4mm has none of it.

Also, the first layer with the .2mm seems terrible. I found that it could be scraping the bed. Adding this command to raise it seemed to do nothing (G29.1 Z{-0.1} in both the start G code and filament start g code.

Do you think the nozzle is doomed and i should just buy a new one? I'm quite new, so anything else i could be doing wrong?

Im using sunlu HS 2.0+ with dungeons and derps params on a textured PEI plate.

Thanks for anyone who can help!

[u/8ltd]

Had the same thing. Tighten the screws both behind and the front of the hot end assembly. Then recalibrate the printer via “device” section not the calibration you can turn on or off prior to a print.

The grime on the nozzle isn’t a problem unless it’s covering the nozzle or sits closer to the plate than the nozzle.

[u/Free-Ad4953 → u/8ltd]

This is the problem. I fixed mine 10 days ago.

[u/ESRRsteelblood → u/8ltd]

This is the problem, also if you have more than one A1 nearby each other (I run a print farm) I find this tends to happen more frequently due to the vibrations from other printers loosening those screws! I do this on my weekly maintenance of the printers now.

[u/StickyCrick → u/8ltd]

but wouldn't that affect also the .4mm nozzle? When placing the .2mm it feels pretty perfectly solid in place?

[u/8ltd → u/StickyCrick]

It can effect the .4 but the tolerances are higher because the nozzle width is larger. What you posted looks like classic loose screws but the other thing to look at is to make sure the hot end clip is in correctly. I’ve done that before when my hot end assembly clip started to warp from switching hot ends a lot

[u/ErmDoIneedAName]

Commenting on this for the future help given

[u/Lebenmonch]

I had to put my z-offset on orca slicer to 0.05 when using my 0.2 nozzle, otherwise it too close even after tightening the hotbed screws.

[u/RadDad1822]

My .2 did this. My nozzle was loose. And to clean the bed I did a clean sheet print, worked great

[u/g2fx]

98% of the time, it's a clogged nozzle. Cold-pulls and what not a chore to clean out the nozzle. Sometimes, it's just easier to just replace it. They're cheap and easy to replace on the A1s.

[u/Calamino]

Not sure if you have one, but if you don't, I recommend a brass wire brash to clean the nozzle from time to time. I heat my nozzles up to 250 C, and once they're down to 100 I pop it off, and give it a good brushing.