I’m experiencing two main problems with my new (<20h), fully firmware-upgraded & calibrated H2D and I’m looking for opinions/experiences of other folks who own the same machine. For the record I am using a **completely dry** Bambu PETG-HF for the tests.
Problem 1 - holes between outer walls and infill at the top/bottom layers
To mitigate the “holes”, I’ve calibrated the flow, which led to a “correct” flow rate of 1.045 (left) instead of stock 0.95 (right), which feels like a significant change, but does appear to work. It makes me think though there must be something wrong with the printer itself. What do you think? Have you experienced something like this yourself?
Higher flow didn’t appear to help with the first layer being rather underextruded especially in the corners of the bed, which I suppose is additionally caused it not being flat at all. That’s not something I had energy to work on yet, will see next weekend what I can do.
Thoughts? Is this a common problem for the H2D?
Honestly, all that leaves a bit of a bitter taste, because the printer costs a lot of money, and given that it was released many months ago I’d have expected smoother experience with profiles that are well tuned out of the box. You know, “bought it to use it as a tool” mindset, not necessarily because I needed an additional hobby (though I agree in the FDM 3D printing tweaking is difficult to avoid and I am not against it at all - but come on, those are some 3D printer 101 problems ;-)).
Obviously I opened the support tickets, but based on what I’ve gathered, it’ll likely take a loooong time to sort it out. I still can return the printer to the seller, and I’m starting to think it may be a good idea.
For problem one you need to adjust your Flow Dynamic also known as “Pressure advance”. It is different than flow calibration. Basically this is the value that tells the printer when it should start backing off the flow before it contacts the wall. Too early and there will be a gap, too late and there will be budge.
Hi, thanks for the welcoming words and for the response!
Not sure PA is the culprit here. The sharp corners (on the basic cube model) looked fine to me, I’ve thought that’s a good indicator of PA being top notch, no?
I’ve done some more tests, and honestly it looks like a systematic problem, as no matter what filament I use, the default flow is just too conservative.
So this is again petg-hf on stock settings. You can see significant underextrusions.
And it seems 10% is a little bit too much, or PA would need to be adjusted, which is already two parameters to tweak in a printer that should work flawlessly from the factory
And to prove my point on the problem being material independent, here’s a scraper printed in ABS on stock settings.
Would anyone be so generous and print my first test file on their H2D on stock settings and Bambu Lab petg-hf/abs and post the results for comparison? That would likely help dealing with support.
Another week of back-and-forth exchange with Bambu Support. Despite hard evidence, they still refuse to admit there’s a problem with bed evenness (0.26mm bulge compared to the corners as measured with the gauge - process analogous to the one described here).
At the same time, 0.26mm seems small enough that I’d have expected the bed leveling calibration to deal with it no problem. Yet, the first layer is utter crap.
Let me know if you get any feedback, I’ve been trying to resolve flow rate issues for the past 60 days with Bambu Labs and the H2D. I purchased an H2D from Microcenter that was having major issues with print quality and exchanged it with Microcenter. The exchange had printing issues as well as a failing power supply and a failing touch screen (power supply would make VERY loud whining on print head movement and the touch screen would randomly act as if it was being touched and would become unresponsive). Bambu sent out an exchange for that one and I still had printing issues predominately related to flow rate control, after weeks of testing they sent out a new printer head assembly for the third H2D and while it helped a little with print quality it still has extreme issues with flow control.
I just think their quality control is lack luster.
I’ve printed models on my P1S and my friend has printed them on his H2C and they have no issues but the H2D just fails all the time.
Attached is the side by side of the same print with the same materials on an H2C vs my H2D. This is on a machine that has been calibrated and I’ve tried multiple different settings, but the quality difference between the H2D and H2C out of the box is shocking.
Using Bambu PETG-HF. I’ve done all the calibrations available and have tried both my manual flow control and the auto flow control with no real success. I’ve tried the auto-circle contour-hole compensation and it not only increases the print time by nearly 60% but it doesn’t improve the quality by any appreciable amount (it does preserve the small holes slightly better).
My first layer prints are also not great with about 25% of the first layer having issues.
Did you two already run the manual bed tramming and took care about the front screw behind the status bar?
I unsually (for non Bambulab filaments) run the automatic dynamic flow calibration, store and assign the value. Then run the flow rate calibration. I choose the flow from the plate where in the middle of the plate there is no gap between the lines, ignoring the under/over extrusion at the outer walls. After I have set up the resulting flow rate in Bambu studio. I run the manual dynamic flow calibration with the pattern mode (not line). Then I choose the PA value where the 90 degrees corner look the best.
Trammed the bed 6-7 times. Removed the front screw as well. The bed is level according to the instructions, but it is just not flat - look at the picture I attached
Calibrating stock bambu filament should not be required - they say it in their wiki. And besides, to fix my problem I’d have to bump by 10% which is just way too much to be considered normal.
Honestly, I feel like I wasted my money, unnecessarily tried to solve the problem while I could still return the whole thing, and now I am stuck with a very expensive piece of garbage. Lesson learned. Never again.
And no, I don’t believe the support will help. They have no desire to, and have no knowledge really. and besides they respond every 3rd working day, so, my expectations of ever solving this are at all time low.
FYI: Bambu Support decided to send me a heatbed replacement (which is a good news, I think), even though they think my current heatbed unevenness should be compensated for by the leveling algorithm.
I will keep you posted once I get it and replace it.
Mine is exactly the same as yours (and I think they are about all the same from different user’s measurements) and I have absolutely no issue, ABL works and compensate as expected.
I return with some good news. Although the story is more nuanced than I initially thought.
The heatbed Bambu sent me is significantly better - roughly “twice as flat”. Previously the height differences (taking front left corner as 0) were ±0.26mm, now it’s around ±0.15mm. It does seem helpful that the differences are now smaller, but it wouldn’t solve the original problem alone.
I bought a brand new Bambu Textured PEI and printed the first layer on it to compare against the plate that arrived with the printer to eliminate any weird effects that a poorly produced plate could have. Funny thing here is that the new textured plate is… quite different - the grainy texture is stronger and more coarse than on the stock one which somewhat explain why on the stock one I had to lower the Z by 0.1mm to achieve any kind of meaningful quality.
Yes, even after bed replacement, the original textured plate has significant impact on the resulting print quality.
All in all, to achieve the perfect first layer, I had to combine both bed replacement + textured plate replacement. Pictures below.
