H2D - Bugs and Issues - Bambu Lab

[3DTech]

I do like the printer, but it has a few bumps along the way that need to be addressed.

My List of H2D Bugs and Issues:

When performing dual nozzle printing with high-temperature filament and support interface layers, the first layer applied on the last interface layer often suffers from excessive cooling due to the fan turning on at higher speed for overhangs. This results in a weakened layer. To fix this issue, I can reduce the fan speed for overhangs to lower setting, but this adjustment sacrifices the overhang cooling speed for other layers that require a higher fan setting.

80% fan speed for overhangs:

30% fan speed for overhangs:

Solution we need more fan control options added to Bambu Studio with dual nozzle printing.

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Nozzle 250c Bug:

I’ve occasionally noticed though not consistently that when switching nozzles, the nozzle sometimes remains at 250°C after the purge. It doesn’t change to the higher or lower temperature specified in the filament settings.

This bug still is in current in 08 firmware just had PLA do it and was printing at 250c

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Right Nozzles Pruges to much:

The 08 firmware shows improvement, but the studio slicer G-code still needs refinement or settings to fine tune the purge value.

Studio V 2.1.0.59 has had new purge G-code will need to test out.

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Misaligned rear Z rod prevents the print bed from rising.

I haven’t encountered this issue myself, but it needs to be resolved as soon as possible. I’m sharing this here to help others find the fix.

The Fix Steps

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Chamber Temp Logic:

If you have a filament that requires a chamber temperature of 50°C but a bed temperature of 110°C, and when the chamber reaches 55°C, it triggers a warning to open the door to cool it down, the workaround is to set the chamber to 55°C. However, this results in the heater turning on at times when it’s not actually necessary.

Solution: The chamber temperature is set to a sample of 50°C, with an adjustable maximum temperature limit, such as 60°C. If the temperature exceeds this limit, the printer will issue a hot chamber warning message.

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High Temperature Support Filament Added

Solution: Yes, you can work around the issue by using a high temperature filament like ASA, but this isn’t a beginner friendly way.

Sample
HT-BW (High-Temperature Breakaway)

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Z Hop:

Add an option in Bambu Studio to enable Z-hop exclusively on the top surface, bottom surface, or both.

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Bambu Links

H2D

HMS Code Index

AMS 2 Pro

AMS HT

Technical Ticket

If you encounter any other issues, feel free to add them to this post. Your input could help Bambu Lab identify and resolve problems more quickly, as they do have a link to this post @SupportAssistant

Updated: 6/03/2025

[3DTech]

I also posted this information in the Z band thread, but since that thread is so long, it might get overlooked so I wanted to share it here as well.

The filament I used for testing was eSun Pro PLA black @ 215c FYI.

Bambu filament fan settings you can see lines and also feel the big middle line with your fingernail. I was trying to capture the photo to highlight the big lip.

I adjusted the fan settings on this test part to eliminate the big 0.2 mm wall band that appeared in the middle. The wall thickness was scaled down from 10 mm to 4.40 mm and then to 2 mm, which caused the plastic to cool at different rates the infill was 15% rectillinear so the wall looks smooth and great now.

The lower fan settings I used in this test aren’t a universal solution for PLA or other prints, but they offer alternative cooling strategies that are worth exploring when working with PLA filament and various part designs.

[sinatra]

@3DTech

Chamber Temp Logic:

If you have a filament that requires a chamber temperature of 50°C but a bed temperature of 110°C, and when the chamber reaches 55°C, it triggers a warning to open the door to cool it down, the workaround is to set the chamber to 55°C. However, this results in the heater turning on at times when it’s not actually necessary.

Solution: The chamber temperature is set to a sample of 50°C, with an adjustable maximum temperature limit, such as 60°C. If the temperature exceeds this limit, the printer will issue a hot chamber warning message.

I will need to test this again after firmware 08 or let me know.

I agree, I only need my ASA profile to be at a minimum of 45C. On consecutive prints, with the chamber temperature already elevated, I receive a warning for no reason to cool the chamber. The logic for any heated chamber profile should be based on a minimum temperature, not a +/-2C range.

[Chubbynub]

so idk if anyone else see’s it as an issue but i had a spool just about out and instead of printing it all it purged the last bit of it after the ams stopped detecting it!

[user_1732300434]

Since the last update, my printer is being random with identifying what nozzles it’s using. Keeps pausing the start of the print to tell me it can recognise the nozzles.

[MotoGP11991]

Have you checked to see if the camera lense in the top front left corner is clean?

@user_1732300434

Since the last update, my printer is being random with identifying what nozzles it’s using. Keeps pausing the start of the print to tell me it can recognise the nozzles.

[MotoGP11991]

@Chubbynub

so idk if anyone else see’s it as an issue but i had a spool just about out and instead of printing it all it purged the last bit of it after the ams stopped detecting it!

It does that on purpose to get rid of the filament so you don’t have to pull it out by hand. However I feel they should be able to figure out where it is more accurately with the sensor in the buffer and another in the tool head so we don’t waste so much. Maybe they do, and I just haven’t noticed it. I thought on the H2D it did a better job of this than my A1 mini. I seem to never be in the room when it runs out.

EDIT: Haha, I just went in my office and it ran out. Mine sensed the filament ran out and stopped printing once it go to the top of the tool head. And then only purged what was in the tool head/hotend. This seems more than acceptable to me. This way they can make sure to get all the air pockets out. On the A1 mini, it purges all the way from the AMS lite to the hotend, which is excessive.

[user_2976819060]

Hi all, I ran into a strange problem with my H2D on the latest firmware (08). Though the printer prints well, it seems that when loading/unloading filament, the printer uses the minimum temperature of the filament previously loaded into the printer as opposed to the normal printing temperature, and on some filaments (the problematic filament for me is the support for PLA/PETG), the low temperature creates too much resistance for the extruder to melt the filament already in the nozzle. In this case the extruder makes clicking sounds and nothing is extruded. In one instance this happened during the preparation stage of a long print, and I was shown the dreaded ‘extruder overloaded’ error.

For example, if my last filament is Support for PLA/PETG, with a minimum temperature of 190, I can try loading another filament, and the printer will then only heat up the nozzle to 190 degrees before trying to extrude and purge. A lot of times, 190 degrees is not hot enough to allow for Support for PLA/PETG to extrude, so the extruder clicks and the loading process fails.

I initially suspected maybe the left nozzle (which this problem occured on initally) slightly colder than the thermistor reading, but after cross checking the filament with the right nozzle (and an A1 mini for good measure), I found that none of them were able to reliably extrude Support for PLA/PETG reliably at the minimum 190 degree temperature. Raising the temperature by as little as 5 degrees sometimes allows it to extrude.

The loading & purging routine on the A1 in my experience will always raise the nozzle temperature to 250 degrees even for relatively low temperatures such as PLA or Support for PLA/PETG, so there was never a problem like this.

Has anyone else experienced this issue? In my opinion Bambu Lab should probably increase the filament loading/unloading/purging temperature from the minimum temperature to the normal printing temperature, or even the maximum temperature (like the A1), which would be more reliable.

I’ve attached some photos to show the printer attempting to load PETG HF (230 degrees minimum temperature) while only heating thr nozzle to 190 degrees due to the previous filament being Support for PLA/PETG.

[PickleEngineering]

I only saw it use the maximum temp. The only reason I know this is because it keeps foaming my TPU at 250c even though the filament profile says to print at 190c. It seems to take whatever the maximum value is for the filament based on the AMS configuration. At least that is how it behaved for me with TPU on an external spool.

I never did figure out a good solution to prevent the printer from foaming a bunch of TPU in the nozzle when ‘changing filament’ which it doesn’t actually need to do since the filament was never switched out.

[Chubbynub]

Mine purged all the filament from the nozzle to the ams like 2 feet of filament. Must have been a fluke because my p1s just purges after it gets down to the tool head.

[StreetSports]

The printer has no way of pulling back once its out of the ams. If the extruder cut the filament, it would just sit in the ptfe tube until you manually removed it.

[TheThirstyFrogs]

Glad I saw your post, I just realised I have the same problem with PVA. I’musing left nozzle to print PLA and right to print PVA support, and when that starts heating up to do the interface layer, its ramping up to 250C and spending ages cleaning and homing and whatever… meanwhile it’s burning the PVA in the hotend. When it comes time a minute or more later to extrude, its jammed and I hear extruder clicking and “extruder overload” error pops up.

Then go through manually clearing it, and the blockages is a burnt yellow, and because it’s PVA it also swells up which jams it up harder.

I can’t figure out why it goes to 250C when I’ve set upper limit on the PVA filament to 230C, Maybe I’m not seeing some extra setting? Also, not sure why it lingers so long either, I expected the filament (already loaded) to ramp up to 230C, immediately start flushing about a cm or two, wipe, and get straight to printing. Is my expectation faulty?

[hotellonely]

It’s spending ages to clean and homing because you have demp pva. demp pva easily jams any motors and gears. it’s not because of temp, it’s just what it is…
Also demp pva makes it impossible to do pressure advance (K value) test. So the sensor can never get a usable value from it. So it just repeats and eventually get wrecked.

[3DRD]

Support claims it’s a known issue. They plan to correct in the next update, and until then they recommend removing the plastic cover over the nozzles (extruder cover).

[TheThirstyFrogs]

I dried it at 85 degC for 24 hours, with fresh dessicant. I’m not sure I could do more to dry it out. I’m starting to suspect the filament profile I set temp limit of 230 degC on is not the one that was actually used. I’ve also read that the default volumetric flow rate is too high and should be set between 1 and 3 and the Ramming Rate set at -1 uses that default. So could be what started the issue. I’ve set Volumetric flow rate to 2 and ramming to 10 mm3/s. Also cleared out the nozzle completely over days, removing some hard-baked on material inside using a 0.375mm drill bit which worked well water soak and needle did not clear it). I will do more experiments this weekend and update here if it works.

[hotellonely]

Yeah if you dried it like that then it’s definitely a profile issue. What was the filament (brand)and which profile you were using?

[Qjo]

Anyone else getting terrible top surface quality with PETG? Filaments have been dried thoroughly, ran both filament calibrations, and even slowed things down a little bit.

The calibration tabs that I picked were nearly perfect. Super smooth. Started a print and the top surfaces are all seemingly way over extruded. Every other aspect of the print is perfect though.

[3DTech]

I use a 0.38 mm line width and a 0.95 flow ratio for the top surface when printing PETG, with a maximum top speed setting of 100 mm/s.

See if that makes a difference with your filament.

[Qjo]

I’ll give it a shot. Thanks for the tip! Kind of sucks that it can’t just print good like the test prints do. I wonder why it’s so different. Maybe the settings for the flow rate tests have these setting adjustments already.