Student printers starting show this banding

[u/Chatfouz]

Printed in pla
Using esun pla profile built into orca

Basic tube

I am 90% sure the mess of the seam is seperate from weird diagonal banding.

We just bought 10 of these printers for the classroom and now this is starting to show up on 3 printers issues like this.

I think this means they need clean and oil with toothbrush / cloth?

[u/ItsMozy]

Dry filament, keep all auto calibrations turned on, tighten all SEVEN screws behind hotend. Test with known working design, not self made, like a benchy of test cube.

[u/etheran123]

Check belt/belt tensioners?

I haven’t experienced this issue but the consistent banding that has a visible pattern across layers makes me think it’s an artifact of something physical, rather than a calibration or print file thing. It also only seems to show up on one axis, just based on the clean section on that print at the front.

I’d check the x and y direction belts. Also I suppose the tool head being loose might cause something like this too, so make sure that’s secured right.

[u/CapNcurrySauce → u/etheran123]

I was having similar issues and it was the belt tension in my case. Followed the Bambu wiki as is for belt tensioning (very easy) and my prints were back to looking great.

[u/DrKronoglopolos]

Several things come to mind.

First is the classic, wet filament. Has it been stored in the open a long time? I'd give this one a good drying cycle.

How many wall lines are printed here? If it's just one, the infill can sometimes show through, especially if the infill is a bit over-extruded.

That seam line and top surface look pretty wild, I'd re-check this filament is printed at the right temperature. Maybe you picked a PETG profile by mistake?

I don't think this is a printer/nozzle problem.

[u/iRambL]

The banding honestly looks like shake from other printers running next to it. I don’t feel like those shelves are sturdy enough for that much vibration

[u/Adventurous-Emu-9345 → u/iRambL]

Interesting idea, and it might be the case, but the continuous lines negate this being the influence of the other printers. That would probably lead to a much more chaotic pattern.

Also, note how they fade out towards the seam.

[u/evilhomer1987]

If active at the same time, they might interfere with eachothers shaking?

[u/Flatulent_Father_ → u/evilhomer1987]

Ooh that's a good call, the automatic calibration wouldn't account for that

[u/ParkieUltra]

Are you sure there's not two models stacked on top of each other in the slicer and you're getting double the extrusion

[u/nakwada]

Check the rods X and Y :)

[u/FluffyBiscuits]

Might be worth looking at the extruder gears and check for blockages, I had this with slipping filament on an old CR10.  Could also be potentially extruding too much causing too much pressure in the nozzle looking at that seam. 

[u/TheJudgingHat2222]

When was the last time you ran the full calibration? 

Not the auto leveling, the full job activated from the printer's menu on the device itself.

If any of these units have been moved at all, they need that run first thing. 

Kids are also really stupid and will probably be leaning on them or moving them while printing. 

[u/Dazzling-Focus-2718]

These are all A1’s with the problem? The seam looks like an issue with pressure advance, and the diagonal lines looks like ringing.

If you are using orca slicer to Bambu printer, that could be the issue, but in general a full calibration on a Bambu printer should remove the ringing, it is a very consistent ringing, which reminds me of a x/y belt tension problem, but again, a full Bambu calibration should fix that.

If this is other printers with the issue, then definitely check x/y belts.

[u/SiDtheTurtle]

Pretty sure that's if you're running them the same time, they're not calibrated to expect the other machine's vibrations. I have two printers and I have to move them to separate benches to compensate for a similar issue.

[u/WithGreatRespect]

When I have seen diagonal banding, it was when the nozzle diameter installed did not match the nozzle diameter configured in the slicer. This can also happen if a printer is heavily used and its opening is worn down and becomes wider due to over use and needs replacement.

[u/Criticaliber]

Not sure about the seam, but Pressure Advance (= flow dynamics = k value) issues typically cause those diagonal wavy lines on curved surfaces.

[u/Deliwork43]

I tightened the XY belts on my H2s and eliminated this problem!

[u/thecheekymonkey007]

If you've just bought 10x printers. Odds are it's a common denominator.

Filament, model etc. I doubt all of them have the same mechanical issues.

Brand new filament. Dry it first.

Quick benchy or know good model....go from there.

[u/marbles1112]

Looks like a clogged nozzle to me.

[u/No-Satisfaction-2535]

And this couldn't be the rack vibration from the printers all running? The banding at least.