For some unknown reason they probably have changed something regarding to the left nozzle’s bed mesh.
This is what I was getting with 1.01.03: the white part is printed with left nozzle.
I did a factory reset, redo every calibration step, then it simply went from Z too high to Z too low (I got tons of wavy patterns).
Then I downgraded my firmware back to 1.02.08 (latest production firmware), this is what I’m getting from the exact same file:
Perfect white area, printed with the left nozzle.
All I did is to just downgrade back and redo calibrations.
My previous theory of they changed the calibration process was totally wrong, thanks to @philch who pointed out and shared the wiki info here. I also monitored the entire calibration process and made sure that yes it is indeed the same.
But the result is still, new beta firmware= bad first layer for left nozzle; old firmware = great first layer for left nozzle. Even if nothing else has changed.
@SupportAssistant please fix it before this firmware get released to the public again. The expected behaviour is that the left nozzle should do both the sparse probing and the detailed probing in both Auto Bed Calibration and High Temperature Bed Calibration. Just as what it was in previous firmwares.
I can’t say for sure, but this looks more like poor adhesion rather than a calibration issue.
When I print a full bed sheet on my X1 Carbon with too low bed temperature, I get exactly the same result as the left part of your image. Once I raise the bed temperature to the correct value, I get a solid sheet that releases cleanly.
I also tried a full bed sheet utilizing both nozzles on my H2D, and it came out as a solid two-colored sheet.
I’m on the latest beta, and as far as I know, my full calibration runs both nozzles. Even if it doesn’t, the prints still come out fine.
no. just try it yourself. do a bed calibration and then run a single layer left nozzle test. You would be surprised.
also it has nothing to do with bed adhesion, the plate is a PLU plate that is capable to stick your fingers on it
but the real reason is that I didn’t post the photo of leftover parts of that test print.
This is what it actually looks like in slicer. The rightmost black part printed with the right nozzle is having a much better performance than the white area printed with left nozzle.
Please @supportasistant, don’t do that. @hotellonely, I’m not sure of what you found. I will have to check but I think you still get full mesh when you do cold and hot bed full calibration, it is then kept in memory and during actual printing, auto bed levelling will only mesh around the model and verify or compensate for any deviations compared to what was recorded. If it were to do a full mesh at every print, I would scream.
I’m not talking about the bed mesh before the print. I’m talking about the full bed mesh calibration that you do after for example a factory reset. Even after a factory reset, it’s still skipping all these steps for the left nozzle:
Full bed mesh (dense/detailed)
High temp bed mesh (sparse and dense)
If you do a full calibration(including motor noise and vibration comp/input shaper…etc), you would notice that even though the estimated time is ~1hr, what it actually spent is MUCH LESS THAN THAT, somewhere like 20-40 minutes is all it takes. Because it’s skipping those steps.
OK, I will do it but I don’t remember this. Now if it is meshed, it is meshed whether on right or left nozzle, you don’t really need both, a simple difference on one of the mesh point between both nozzles should be enough if one of the nozzle has performed a complete detailed mesh already.
It’s 100% not enough. Which is why before 1.01.03 Beta the full calibration would take more than an hour. And it print flawlessly on my machine.
The whole point of doing a bed mesh for both nozzle is to remove any uncertainty. Which in fact exists.
Now I have reverted back to the previous public firmware, and I can confirm that the behavior is different and it’s doing the calibration right without skipping those steps I mentioned.
The calibration shouldn’t matter, the important thing is the result. What does your test on the current production release look like? I’m assuming your first layer issues are solved?
Also why would you want to run a full bed mesh with both nozzles, surely one nozzle is enough assuming the machine is operating normally and you can determine the offset between nozzles. Even if the bed was out of tram I would think it could still be worked out mathematically.
No. Surely it’s not good enough. Which is why they were doing the right thing (full probing both nozzles) previously.
A lot of errors especially mechanical errors can happen here and there, and with a nozzle moving up and down, mounted in different angles, having different nozzle wearouts, and different structural thermal expansions… it’s not just that “ideal world” situation. With ideal world you can of course just get by with a single bed mesh and a nozzle offset.
But in reality, it could be two totally different bed mesh. At least different enough to make a first layer go from gem to trash.
Are we expected to run a full 1 hr bed leveling every time we change nozzles? Since the position would be changed slightly surely.
I have changed nozzles a bunch of times and only run the full bed leveling twice, once when I got the machine and another time when I re-ran all calibrations. I have yet to run into any general adhesion issues that are affecting one nozzle and not the other. What exactly is happening mechanically that cannot be compensated for assuming that both nozzles are within tolerances? Perhaps it being run for both nozzles previously was an oversight.
From Bambu’s official wiki, yes you’re supposed to run a full bed calibration after nozzle swap. Or even a plate swap. Again you can getby with it but that would have effects either noticeable or not noticeable for your prints.
@hotellonely Did you pull a ticket? I don’t think we can count on Bambulab reading any forum posts at all. On rare occasions they may pay attention and comment, but it seems much more the exception than the rule.
Regardless, thanks for the heads up!
IMHO, being able to get a high quality “perfect first layer test” is essential. One might get lucky in executing a print even if it is bad, but I think it’s just russian roulette as to the outcome. So, for that reason, to me it’s a red flag full stop if the “perfect first layer test” isn’t coming out well.
It’s not clear that the hotend latching mechanism is all that precise in its vertical alignment, so I wouldn’t be surprised if a new bed leveling is required even if you were to remount the very same nozzle.
Of course, if we had transparency into the bed leveling data, would could test this hypothesis ourselves, but we are denied that access by Bambu, and for now, Bambu doesn’t provide a way for us to see. As compared to Klipper, for example, where you can actually see the bed leveling measurements at each and every point of the bed leveling matrix.
I did pull a ticket, but my test results are strange. I’ll update when I have more information on hand. Actually the previous production firmware (1.01.02.08) was doing the same thing (skipping most of the left nozzle calibrations).
Q: There are several types of heatbed leveling for printers. What are the differences between them?
Auto bed leveling on the Print calibration page
Heat the nozzle to 140°C;
With the bed at room temperature, perform an 8×8 point leveling using the right nozzle;
Heat the bed to 55°C, then perform another 8×8 point leveling with the right nozzle;
Continue with a 22×22 point leveling using the right nozzle;
Finally, switch to the left nozzle and perform an 8×8 point leveling.
High-temperature bed leveling on the Print calibration page
Heat the bed to 100°C while heating the nozzle to 140°C;
Use the right nozzle to perform the following leveling steps:
8×8 point leveling
22×22 point leveling
Note: The high-temperature bed leveling data will be automatically applied when the bed temperature during the print job is ≥ 80°C.Suppose you have replaced, disassembled, or manually leveled the bed. In that case,it is recommended to run both Auto Bed Leveling and High-Temperature Bed Leveling againonthePrint Calibration page to ensure the machine obtains accurate bed plane data.
Auto Bed leveling before printing
When “Auto” mode is selected:
Before printing, a 5-point touch test will be performed on the corresponding areas of the model contour to determine whether partial leveling is needed.
If partial leveling is required, use the 8×8 leveling points that cover the model’s projection contour on the bed for leveling.
If not required, skip the partial leveling step.
When “On” mode is selected:
Directly perform partial leveling on the model contour area on the print bed.
Note: The partial leveling data and calibration leveling data (including Auto Bed Leveling and High-Temperature Bed Leveling) will be stored in the printer. During printing, the system will automatically combine and apply both sets of leveling data. This data remains effective until a new corresponding leveling task is performed to update it.
Auto Bed Leveling during the unboxing process
1. Initial Leveling:
Heat the nozzle to 140°C;
With the bed at room temperature, perform an 8×8 point leveling using the right nozzle.
2. Post-Heating Leveling:
Heat the bed to 55°C;
Perform another 8×8 point leveling using the right nozzle.
3. Nozzle-Switching Leveling:
Switch to the left nozzle and perform an 8×8 point leveling again.
This is a long-shot suggestion, but are you doing a factory reset after loading new firmware? I thought it was urban legend, but now I’m reading it’s officially recommended, especially for resolving peculiar problems.
I notice that a number of posters mention doing it as a matter of routine whenever they do a firmware upgrade. I never have, but I think I’m going to start, as I am already re-running all of the optimization programs anyway.
I just hope it remembers the wifi password! I have a long one that’s randomized and difficult to enter. However, I presume a true factory reset will probably wipe it out.
