I’m getting a distinct banding pattern on the sides of prints. The bands are pronounced ridges and are in a diagonal nature. See attached photos. The printer in question is a P1S.
I’ve printed this model many, many times, and because of this failed print I reprinted it on another P1S with the exact same settings and it came out flawless.
I’ve re-tensioned the belts, per Bambu Labs’ instructions, I’ve cleaned and re-lubricated the lead screws, I’ve cleaned the carbon rods per Bambu Labs’ instructions, and still the problem remains.
Anyone else have experience with this particular problem?
As an update I’ve also swapped out the extruder and nozzle now, as well as made sure spindles that the belts wrap around are clean and free of debris.
That’s wild and is very aestheticly pleasing, if it were part of the model lol. Interested to hear what they say. I’d imagine something mechanical in the corexy motion system, for it to line up across layers and slightly out of phase. Caliper those grooves, 2mm apart? 2mm is the belt tooth size [iirc]
Lead screws damaged? But it would create horizontal banding, certainly not create so good looking diagonal banding, like the outter skin has been applied screw effect.
Somehow, your printer was possessed by 3D printer ghost?
Groove seem to vary in size depending on the printed part’s size believe it or not. Even more odd.
Don’t think you’re far off there. 
Been racking my brain for days on this one. Sent a support ticket in, but haven’t heard back yet. Tried every maintenance and troubleshooting approach I can think of.
This was a vase mode print using Bambu PLA-Silk. The diagonal lines were repeatable and almost exactly the same every time. They appeared only with PLA-Silk; PLA-Basic, Matte and Metal were all fine.
This was several months ago, but after wasting too much time on it, my conclusion was that it’s either harmonics or ghosts.
The filament has no bearing in my tests. Same with all filaments I’ve tested. Additionally you lines are curved upwards in a slight arc it seems, while my example shows a straight diagonal, so I’d guess our problems are not the same in this case IMHO.
No, not the same, but likely from the same root cause.
I made several adjustments, both physical and in the print profile; each time the pattern would change slightly. After awhile I concluded they were transitional Z axis artifacts created by mechanical resonance. Or ghosts.
One reference guide called them noise. It stands to reason your resonance, and your ghosts, would not be the same as mine.
The issue in the photo is primarily due to dirt on the idler pulley. Please refer to the Wiki link provided for cleaning instructions.
[How to Clean the Idler Pulleys of a 3D Printer | Bambu Lab Wiki]
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Thanks for the reply. Unfortunately this is something that was suggested by Bambu Lab support and I went over it with them, cleaned all of the idlers and the belts and the problem persisted. After much back and forth with Bambu Lab support, videos and images exchanged, etc, there was never a solution that fixed the problem.
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hi, did you ever find the fix for this?
Hey there, thought I’d chime in as I just solved this exact issue for my print farm, I’ve been having diagonal banding on prints for a while, and do all the usual fixes, and amazingly it does go away a little for a few days or even weeks sometimes, but always comes back - until I did this last fix:
Following the Bambu Lab Wiki on the idler pulleys: I know we’ve all already done it, but have you removed the two in the back, and then scraped all gunk off of all 12 (yes Twelve), on several you simply cannot clean them, and can not even barely SEE them least of all clean them properly, luckily this person created a tool just to clean the pulleys, link below, I printed 6 out and used each twice and wiped the gunk off with. IPA and WD40 between uses, and you have to really move the toolhead around and PRESS the tool into the pulley to the point that it ceases sometimes to really get the black gunk off. that gunk is what causes it for my printers. I did this to ALL of them in an afternoon, and now they print like the image on the right - it’s not a huge improvement (this was the oldest unit with over 7,500 hrs on it and needs a few other fixes) but it solved the diagonal banding that got so wavy it was noticeable in normal lighting.
You can only clean the rear pulleys by removing the plastic blocks next to them, and their screws completely, and they slide right out, and you can use the tool on these too. For some of the pulleys, I literally had to get an exacto knife to get the gunk off, it was solid hardened in several of them, like the ones on the BACK of the carriage.
https://makerworld.com/en/models/1167368-idler-pulley-cleaner-for-bambu-lab-p-c-e-series?from=search#profileId-1175040
Hope this helps
one more before and after pic - that is pure physical moire up in there!!
