By broken I don’t mean that it won’t work, but it’s severely flawed. I don’t know when it happened since I normally send everything through Orca. And it’s also not just Bambu Studio software, since the issue happens when sending through the app with cloud slicing as well.
For context, I made a model of the ball that Bambu uses to show their filaments. I print it with every new filament and color that I get, I’ve made dozens without issue, so the model is 100% not the problem nor is the print profile.
The issue probably won’t effect all models, but it is very apparent with this particular one and it has to do with the speed consistency.
As you can see in the screenshots, the first one with rapid speed changes is Bambu Studio. The 2nd one with a consistent speed is Orca. Every setting is exactly the same, the filament profile is exactly the same. Bambu Studio USED to slice it with a consistent speed like Orca, but as of right now, it does not.
Also, this is not happening with PLA profiles, they slice and print as expected. But when I sent prints with PETG profiles, they turned out horrible and this inconsistent speed is the reason why. I also went and tested slicing with other filaments, it appears to happen with ABS and ASA profiles as well, but none of the PLA profiles that I checked. I also didn’t check any of the other types.
It’s hard to get a good picture of the result, especially since I printed black. But here’s a comparison, the left sent via Bambu, the right sent via Orca. Both printed with Bambu Basic PETG. Ignore the size difference, it’s the exact same file and print settings. The Bambu one broke off a few of the bottom layers when I took it off the plate. Whether it’s sent through Bambu Studio or the Handy App, it turns out like the left.
I don’t know why you thought to move this to the Bambu Studio section. As I specifically said it’s not a Bambu Studio issue. It is a slicing issue with BOTH Bambu Studio and cloud slicing via the app through makerworld. Moving it only makes less people aware of the issue…
If you’re going to move my post, which I disagree with doing. At least move it to a correct section.
It’s a software issue, what I said is that it’s not only limited to bambu studio. The same problem occurs through the app with any profile other than PLA variants.
Something is limiting the rate on orca to be very slow, if you apply the same limit to studio it will be equally consistent. Conversely, if you can remove the limit from orca, it will be as inconsistent as studio.
Incorrect, when I said exactly the same, I meant exactly the same.
It’s a print profile that has had no problems for over 6 months, also doesn’t occur with PLA filament profiles. If you actually look at the screenshot you’ll see it speeds UP on the steeper overhang areas while going slower on the rest. The opposite of what it should be doing.
It’s a problem related to the cooling overhang threshold. And as I stated, it’s a somewhat recent problem. Not sure exactly which update caused it since I usually send prints through Orca, and the latest things I’ve sent through Bambu Studio have all been PLA. But I’ve printed dozens of these in PETG and some in ASA via the app without issue before.
I’m trying to replicate it, I’m using your mw 3mf and setting it to “generic petg”. The orcaslicer behavior is different, but I can’t replicate your speeds in studio 1.9, but 1.7 looks very similar to the results you were getting.
Can you supply a test .3mf set exactly as you like, and exactly which version (broken) you are using now and which version (roughly) in the past worked properly for you?
I haven’t done anything special really, just switched the filament profile. Whether it’s my custom calibrated profiles or default ones, anything but PLA seems to cause it. From what I’ve figured out it’s caused by the cooling overhang threshold setting found in the filament profiles. PETG for example defaults to 10%, whereas PLA defaults to 50%.
You can recreate the problem with PLA profiles by lowering that setting, which causes a similar result of speeding up where it shouldn’t. Likewise on other filament types, increasing it back to 50-75% will “fix” it. For this particular model though with PETG, even 50% has some issues with the lower sections, but 75% gets rid of it.
You can make Orca slice it with varying speeds by disabling slow-down completely. However it does so correctly, by slowing down on overhangs, not speeding up or changing speeds rapidly. It also is unaffected by the threshold setting, whether it’s 10% or maxed, it all slices normally in Orca. As it used to in Bambu studio as well.
If you want to see it for yourself with the specific model, it’s the Bambu Ball on my profile.
I’m not about to go reinstalling old versions of studio to find which one broke it. It could be the latest update, could be one or two before. I don’t even keep track of when it updates. I’ll just let Bambu Lab figure that one out.
Quality>Advanced>Smooth Speed Discontinuity Area and Smooth Coefficient
This makes my overhangs on PETG absolute trash due to all the speed changes. I left it on and set the coefficient to 0.1 and then set all ‘slow down for overhangs’ speeds to a single slow speed that I want (it is a somewhat organic loft where overhang areas change % overhang often for a given wall). This resolved the issues for me and got my ‘speed’ slice view to look like constant velocity and the part finally comes out perfect.
Almost everywhere the speed changes on those overhangs would leave some kind of visible mark. It makes me think something is very wrong as I believe the product should accommodate acceleration while printing and usually does quite well. Then again perhaps I have my volumetric flow set a bit too high for PETG-HF and it creates the issue.
I noticed that setting as well and played around with it but it made no difference in my case. Enabled, disabled, set to minimum and as high as 8000, all results were the same.
It can be forced to be consistent by lowering all speeds, but that’s just a bandaid.
@krell, The .3mf is literally the one on my model’s page…
