My H2D has produced good single layer prints with both nozzles and PLA. The front lower bed screw was already backed off enough. The HF PETG required a slight Z-offset adjustment, which I added to the filament’s start G-code.
Refer to the revised method a few row down if you currently need to adjust your Z-offset
The newly released Beta firmware V01.01.02.07 mentions Optimizing first-layer quality , so they may have improved it specifically for the type of filament being used.
This was with the smooth PEI plate.
If you notice small PETG ripples or waves, with the stock settings you need to adjust the Z-offset with this code.
Mine turned out perfectly with a 0.05
My initial method.
G29.1 Z0.05 ; To adjust the nozzle Z gap fine-tuning in increments of 0.01, either up or down
Even with my printer set to LAN mode and I’m not logged into Bambu Studio, some of my custom filament settings will get removed. While the code above will work, it has to be very basic G-code or it will remove the custom filament G-code settings and not load it on reboot.
Always make sure to keep a backup of the configuration folder.
If you need to fix it you have to edit the JSON File.
I haven’t noticed the need to adjust Z offset. The one time I got the ripples with PETG was because it didn’t probe the bed before the print, it just did the quick check.
I cancelled that print, switched auto bed leveling to on instead of auto, and sent the print. First layer was perfect after letting it do probing.
I have since switched it to on instead of auto for every print just to ensure the first layer is good.
I’ve tested both the ‘On’ and ‘Auto’ modes on my printer using HF-PETG. With the proper Z-offsets, I can consistently achieve a flawless full bed sheet with both nozzles, and PETG tends to perform better with larger Z gaps.
If your PETG filament is performing well, there’s no reason to make any changes.
My PLA printed flawlessly on the full bed sheet test using both nozzles, even straight out of the box. The stock offsets performed well, as we all know PLA works fine with tight Z-offsets. I also got fortunate that the front bed screw was already loosened and confirmed it wasn’t bottomed out.
Modifying the H2D G-code isn’t as straightforward as it was on the X1C. I’ve added custom purge settings and believe I’ve resolved the occasional 250°C nozzle error in the start G-code by adding an M104 command to the nozzle load line. However, I’m still testing it since the issue was quite intermittent on my machine so far, I’ve only seen one other person report it as well.
Revised method for utilizing both plates with necessary Z offsets applied as needed, while retaining the settings.
Save the current machine (Save Icon), then modify the Machine Start G-code and save the updated changes.
This Z-offset is set for my HF-PETG; you may need to adjust yours for optimal results.
;===== for PEI Plates , lower the nozzle as the nozzle was touching topmost of the texture when homing ==
{if curr_bed_type=="Textured PEI Plate"}
G29.1 Z{0.02} ; for Textured PEI Plate = Bambu Lab default -0.02
{else}
G29.1 Z{0.05} ; for Smooth PEI Plate = Bambu Lab default 0.00
{endif}
If you’re new to this, here’s what happens when the Z is set too low for materials like HF-PETG on first layer and this was not my printer this is a sample photo.
Yea, I keep thinking of why I’d need to do this for PETG alone and can’t come up with a reason. I have adjusted my Z offset on my x1-c for a specific plate before, but never for specific filaments. And that’s only because I use the textured plate setting for a not so textured plate. You might have an issue with your machine if this is necessary.
The only time I’ve ran into something similar was with my QIDI plus 4 before I sold it. I had to set different Z offsets for different filaments. Basically the same thing you’re doing. But this wasn’t a filament problem, it was a machine problem. The peizo sensors for the bed would fail at higher temperatures. It’s a well known thing for the plus 4.
The photo was just for reference my H2D printer isn’t actually that bad. I only noticed a few minor issues with HF-PETG, and that was when the entire print bed was covered. There are some slight temperature inconsistencies across the build plate, but the Z-offset gave me a perfect first layer.
If your PETG filament prints well across the entire bed plate, there’s no need to make any adjustments just keep in mind that not all filaments will behave the same way.
This is all nice but can someone tell me with certainty if a negative number value on the G29.1 squishes more (nozzle closer to bed) or less (nozzle farther to the bed) on the build plate ? it is not clear anywhere.
Thank you.
maybe try do a bed tramming process with dial indicator? it’s like 20$ and 2 hours of print time but probably would solve your issue. The need of manually adjusting z offset is just very very strange if PLA works well. It’s a hint of the nozzle being pushed down by the extruder due to high restriction, either by not enough heating/fluidity or parcial clogs or other things like a loose hotend seat. Have you tried to print with the other nozzle?
My guesses:
loose hotend seat: as pla flows easily it’s not gonna push the nozzle down. but for petg because it’s slightly harder to melt so it’s having a slightly higher nozzle pressure, resulting the nozzle to be pushed downwards by the extruder slightly.
not enough heat (inaccurate nozzle temperature), so that the filament won’t be melt well, other users have found this problem but you would need some heat probes to get better measurement.
other things like defective nozzle/partially clogged nozzle…
bed not levelled well enough so combined with temperature difference it revokes the bed mesh…
Probably start by using the other nozzle to print and try without your z-offset adjustments, see if it works. Then tighten all those hotend seat & plate screws. Then if it still doesnt work do the manual bed tramming with dial indicators. Eventually, if it still doesn’t work, well it’s time to call support for a replacement of something…
I have the required tools to manage this, and I’ve successfully dealt with similar situations on my other 3D printers, such as when multiple filaments had problems or the bed plate became warped.
For certain filament types with the H2D, I’ve had to apply a Z-offset.
High-flow PETG passes through the nozzle with greater ease. However, if the nozzle is set too close to the print bed, it may harm the quality of the first layer. As always, I’m aiming for perfection.
Standard PETG flows more slowly, enabling me to use a tighter Z-axis setting or stick with the default G-code offset settings.
The H2D is working properly; it’s not a mechanical problem. I’m able to get my first layer perfect every time.
Keep in mind that different filament types and brands may perform differently.
might sound stupid but have you tried to raise the first layer nozzle temperature probably by 10C? I’m asking because I feel like if you improve the flow of the filament you might get a better result
I fine-tune the nozzle and bedplate temperatures to identify the optimal settings that suit the filament. I use the LCD to make adjustments until I find the perfect balance.
I love how people in this thread somehow think every filament is going to flow or extrude the same and that magically having a bed mesh makes them all lay down first layers the same.
Can tramming the bed help? Sure, but that is irrespective of the filament.
If one filament lays down a perfect first layer and a different one doesn’t, its pretty easy to deduce that the filaments are the issue.
Silk filaments are notorious for needing the raise the nozzle because of their expansion when being extruded.
Are you creating new filaments for the ones where you edit the filament start gcode?
My guess is you aren’t or you are doing “based on xxx filament” instead of “copy filament profile”.
Doing “based on…” has been wonky for a while in orca and settings will get overridden/removed if the base profile changes or just over time for whatever reason.
I am new to Bambu eco system but why don’t they just make this a setting on the printer? I adjusted my creality all the time and never had to deal with Gcode.
Unfortunately, Bambu slicer is quite basic; they should provide more settings for the H2D. I believe it would be better if they offered three user levels Beginner, Advanced, and Pro.
That’s why people had to use Orca Slicer to access extra settings on the other printer sold by Bambu. Hopefully, they’ll improve the slicer soon.
In the time this discussion has been open have we had any of these concerns addressed within the most recent updates ? I skimmed through and could not identify any.
