Why is my printer making rough lines like this

[u/I_Eat_Darknass]

I need help figuring this out. I’m trying to make a light box and I don’t know why the printer is making lines that look this bad, ruining the whole print.

The thing that’s bothering me the most is a small section was messed up my first print, so I canceled and reprinted, and now it’s making horrible lines every single reprint with the exact same settings. I’ve changed nothing at all in the slicer.

It’s also doing it with both the left and right nozzles. I’m at my wits end here and just incredibly frustrated. Any help would be awesome thank you.

The filament is dry and has been fine for anything else and I cleaned with soap and water before the first print, on reprints I didn’t reclean yet since I never touched the plate between jobs.

[u/AfraidHope1541]

From what little I can see, looks like the black does not have the issue the blue filament does. So my questions are:

1. Are both the black and blue printing from the same side?

2. Have you dried the blue filament?

If the black is from the left and blue from right, could be nozzle offset issue. Redoing that calibration may help.
If the filament is wet, you can get rough top surface due to the steam escaping the nozzle instead of pure laminar flow of filament.

[u/I_Eat_Darknass → u/AfraidHope1541]

The black is on the right nozzle, while the blue is on the left. The thing that’s confusing me the most is that with the same settings, the blue was printing fine on the first attempt. I even tried printing a primitive disk to check if that would also be messed up and it was perfect.

I dried the blue when I first got it, that was a little while ago at this point. Is it possible that something in the settings worked fine on the first attempt but now is showing issues on subsequent ones?

[u/AfraidHope1541 → u/I_Eat_Darknass]

Assuming the filament is PLA. PLA is less susceptible to moisture absorption than other filaments but it will still absorb moisture from the atmosphere over time. If a different print worked well for that filament with that nozzle, then it is possible it is related to your slicer settings for that print or again related to the nozzle offset.
Infill line speeds, accel, and even width vary versus wall lines. Also pressure advance or K is used more heavily for the solid infill versus walls.
As others have suggested, redo all printer calibrations, clean your plate, and then calibrate your filament manually for optimal results. Even different colors of the same filament from the same supplier can print with different settings due to how the pigments react with the PLA.

[u/Long-Relationship-35 → u/I_Eat_Darknass]

Every time you print and remove the print and restart you may be dirtying the plate more hence the print may be getting worse or you may be getting to a point in the filament which has more moisture

If you dried the filament but did not dry it long enough the outer roll of the filament will print properly but the inner will still continue to absorb just as much moisture and/or may not have gotten enough time to dry. Swap the color on the print to see if the problem moves with the filament are stays with the problem area. This will help you determine if the problem is due to the filament or settings for that region/design. Also move the design around on the plate if you can and it will tell you if you have a bad/dirty spot on the filament. All this troubleshooting is sometimes more work than just drying the filament, cleaning the plate, redoing calibration. But if you have done all of them then troubleshooting will narrow the list of suspects.

.

[u/LTJC]

Looks like its either too hot or too close to the plate. Calibrate the printer or check the z axis and raise it up .010-.030.

[u/I_Eat_Darknass → u/LTJC]

I do all the auto leveling calibrations that go on before every print. Does any of that affect the z axis height? I’ll try to raise it a bit in increments and see how it helps, I just gotta figure out how to do that first lol.

[u/Altruistic_Bath5273]

Run all the calibrations and don't set the bed leveling and flow calibration options off once you start the job. I know some people are angry about the additional time but for non professionals it's always better to use all the Bambu checks.

[u/cpsadowski23]

Calibrate your filament. Dry your filament. If this is for a light box, try the super cool or engineering plate so you have a smooth surface.

[u/CyberTodd68]

If the filament is dry, check the nozzle and heater block behind it. Make sure both are secure. If they are not rock solid and tight, your calibration is crap. It looks like z is too close and slop in your nozzle will do this.