I’ve been printing iterations of a thing i’m designing with no problems and suddenly my top layer is printing like this. the top one in the image is the one showing the top surface.
RVR with Pegs.3mf (130.2 KB)
Calibrate the flow ratio and k-factor and it will look much better again 
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Do you have ironing turned on?
If you do The Mountain Maker (a youtuber) solved that problem by putting the ironing speed at 25 mm/s and putting the ironing flow at 25%
thanks. i’ll try this after the current print is complete.
Thanks. I did turn on ironing for the print currently underway but different settings… i will try this
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I hate to break it to you but this is a classic example of either extremely bad filament tuning or wet filament or both.
What filament are you using and what was the before and after weight when you dried it? Also, what were the results of your calibration efforts? Did you use Orca Slicer to calibrate or did you rely on the the “Calibrate” button in Bambu Studio which is largely ineffective?
One can have wet filament and tune out a lot of sin but not all of it. Even PLA can be wet right out of the factory bag. If you want perfect prints, hand tuning will always yield the best results. If this was printing fine and only now is causing issues, then filament moisture is highly suspected.
Could you please elaborate on this or point to a thread/article about this?
As a noob I would say that I presume things like a calibration button is doing what is says it does.
Thanks!
That’s a fair question. The Calibration feature in Bambu Studio is limited and, at best, a blunt instrument. When the P1 product line launched in 2023, it worked reasonably well for beginners using Bambu’s filament, but its effectiveness quickly diminishes with third-party materials. The X1, despite having LIDAR, has a reputation for inconsistent calibration. I don’t own an X1 myself, but my sons do, and they tell me calibration is hit-or-miss.
A major issue with Bambu’s filament ecosystem is that when they changed the formulation of their Basic PLA, they never properly tested or updated the factory profiles. This has led to unpredictable results, even for users who stick to Bambu’s own filaments. Instead of refining their profiles, they left users to figure it out, which defeats the entire point of a “plug-and-play” system.
When I first got my P1, Bambu’s PLA Basic filaments—especially Black and White—were constantly out of stock. It was frustrating, like buying a razor and realizing the company couldn’t keep blades in stock. But in hindsight, that frustration was a blessing in disguise. It forced me to explore third-party filaments, and what I discovered was eye-opening: many brands source from the same factories. Once you master filament tuning, every spool—regardless of branding—can produce perfect prints.
I previously posted on this topic, detailing how to identify filaments from the same manufacturer. Some users in that thread speculated that Elegoo was Bambu’s original supplier, with the only differences being the plastic spool and RFID tag. Here’s that discussion: So you think your high priced fancy-schmancy filament is the the best? There were many useful responses on that thread.
These days, I pay around $10–$13 per spool for PLA on Amazon, with free 1–2-day shipping. Here’s the kicker: if a filament doesn’t perform after calibration, I return the unused portion for a full refund—Amazon’s policy, not mine. I’ve even sent back 1kg spools after using 500g. Those go on my blacklist spreadsheet. It’s rare, but in my early days of testing, about 1 in 10 brands didn’t make the cut.
I still keep a small stock of Bambu filaments, but only for troubleshooting or comparison. For daily printing, I’ve moved on—and I haven’t looked back. If Bambu can’t even bother to test and update their own filament profiles after reformulating, why should I pay a premium for them?
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For a better understanding of “how,” I recommend these videos, which cover the use of the Orca Slicer Calibration suite. This suite is built into Orca Slicer and includes features not available in Bambu Studio. While there are many videos on this topic, I find this creator particularly thorough, and these are the ones I revisit most often.
This is the missing tab that is not included in Bambu Studio.
Here is the Github wiki tutorial page for Orca.
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Thanks for the input.
My PLA lives in this 160L Cabela’s Dehydrator. I also use Polydriers for PAs (stored with silica containers that color code and get swapped when i use something whose silica has ‘gone pink’ etc to spec before)… i never dry PLA coming out of that box. I run it at 95F maybe about every other day. internal RH never above 10 unless i open the door. The filament thermal mass keeps everythibng pretty warm and dry.
The filament is Matterhackers PLA HS. They have replaced it TWICE because it came on a broken spool that i had to make rings for… no questions asked.
However I have gone back to the filament used in my last good print just to be sure and thrown thje MHPLAHS into a polydryer for six hours at the recommended settings. I also swapped out from an E3Dobxidian to a BBL hardened for shits and giggle. i know i am changing more parameters than optimal per test, but i’m hoping to get lucky.
Are you saying that I can’t manually calibrate in BamStu using the manual calibration where it prints a bunch of thin lines, you pick the most consistent, and save it as a profile for a given filament?
I started my day with that after ending it with attempts ruined by adhesion issues. ran this morning’s on a supertack build plate.
I’d like to add that these lines only appear on the top layer. The print looks great until the top layer.
Ironing and using proven filament directly from the dehydrator print has 4 minutes left and looks better. but 4 minutes is long enought to ■■■■ it all up.
I am going to put wooden dowels in the dehydrator to replace those weak wire shelves. That will actually allow me to vary the hieght and overlap half empty spools. I’ll have to take everything out of the bags to do that, but that’s a remnant of early storage protocol before i decided to use the cabelas for this purpose. wish i hadn’t sold my other one.
Calibration…
Bambu offers a set of 9 patches for you to check.
Pick the best looking and do the fine tuning, with again 9 patches to choose from.
What layer height was use, was a k-factor applied, what print speeds ???
We don’t know…
We also don’t know how those patches translate to the k-factor established …
And what IS the best patch? The cleanest looking one or the ones with the least amount of defects?
For me the Bambu calibration is useless.
Takes too long and is not consistent enough.
Bambu can be off by 0.08 or more for the flow ratio and that’s more than enough to create a mess.
I rather print a few test cubes and do it manually…
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I find that bambu has dumbed it down enough for me to learnm how things work. I’d like to start to get deeper with orca slicer, but now is not tghe moment.
the prints are getting better and i am back to prototyping based on response to this thread. thanks all.