My H2D has been running flawlessly since i got it early this year, but recently I’m getting more issues of warping and the print coming off the build plate. I did wash the buildplate but that didnt really work. Glue is a solution, but I never needed it before.
I’m guessing the the exhaust fan is the main problem. The printer is in a workshop where the temp is now around 15C, as it is winter here. This means it is sucking in cold air, while the chamber isn’t too warm for PLA anyhow. I have been manually closing the exhaust and lowering the AUX fan, but this is becoming a bit annoying.
Are others now also frequently experiencing this? And what is your solution?
Would be great if there would be some update on the software, as it is just a matter of temperature control settings.
it’s not the exhaust fan, it’s the stupid decision of forcing chamber cooling BY DEFAULT for PLA and PETG. They didn’t take colder areas into consideration.
@SupportAssistantPlease please please just give us an option when sending printing tasks, to turn on or off chamber cooling as we wish right before sending a print.
No, modifying the filament profile to turn it off, or modifying the printer profile, isn’t a good way neither a convenient way. Because it’s a pain to map every filament profile manually every time when you’re using multi color or other things. Just give us an option to turn it off by one click please?
Go to the Bambu studio settings and enable “develop mode”.
Then go to your printer profile and enable “enhanced air filtration” and save it. This will be the new printer profile you use and you won’t have to mess with this setting again.
After that, go to your filament profile and navigate to the cooling tab. At the bottom you’ll now see an exhaust fan speed setting. Change it appropriately and save the filament profile. You can also change your aux fan speed here.
Default exhaust fan speed is 30%. Try bringing it down to 20% and see what your chamber temp sits at. PLA can handle up to about 38°c, but it’s probably safer to keep it around 35°c. If you find it’s still too much cooling, try 10%.
I’d probably just totally turn the aux fan off. Set it to 0%. I’ve never actually found that I needed the aux fan, so I’ve converted them into air scrubbers.
For PLA/PETG turning of the AUX fan and chambers fans should help. If you are still having a problems after that you can enable chamber heating at 40c inside the filament profiles.
Thanks to the comment of @Qjo I can now change the exhaust fan from the filament profiles. However, I’m now printing a large, multifilament print now (relic rush board game) and it is really annoying to keep on adjusting these profiles and checking if the fan is now still on. I rather have a simpler solution, which could come from bambulab. Now the chamber can either be set to warming or cooling, with cooling of PLA in a colder room is now the issue. It could be changed to include a third option like neither cooling nor heating, unless a min/max setpoint is reached.
So, I had a quick look (with help of Claude) at the machine start G code where i found:
Auto-Cooling Configuration (For temps <40°C)
M142 P1 R30 S40 T45 U0.3 V0.5 W0.8 O45 How it works: Sets up automatic chamber cooling parameters:
R30: Minimum chamber temp threshold (30°C)
S40/T45: Temperature targets for different stages
U/V/W: Fan speed multipliers at different thresholds (30%, 50%, 80%)
O45: Maximum chamber temp before aggressive cooling
This creates a graduated cooling response based on material type (PLA/TPU vs PETG).
The 30% exhaust fan speed (U0.3) corresponds to what i now see when i do a print with PLA. So perhaps changing this to 10% (U0.1) may be a solution, or increasing the minimum chamber temp threshold (R30) to 35C. However, I never adapted these G code values before so I might be completely wrong here. Also these setting would indicate that 30% exhaust fan only applies when the chamber temp is above 30C, which is not the case for me when printing PLA.
What do you mean by this? You don’t have to keep adjusting it or checking it. Save the profile and you won’t have to adjust it again. As for checking it, you shouldn’t have to do that either. It’s going to do what you tell it to do in the profile. Set it, save it, and forget it. It’s quite simple and doesn’t require any babysitting.
I tend to adjust all my filament profiles as I find defaults are sub par most of the time. So maybe it’s just me thinking it’s easy? If you’re the kind of person to just run default profiles and doesn’t want to mess with settings, then I suppose I can see your point of view of not wanting to change profile settings.
The gcode change may work. Worth a shot if that’s the way you prefer to do it.
Correctly, I tend to use the standard profiles. But for this large project I’m using adjusted profiles for each filament type. I did change the AUX fan speed but didnt’ do the exhaust yet as you suggested. If I select Activate air filtration I can see the fan speed during print is set to 70%. This does not correspond with the 30% I’m seeing. Is this 70% the max fan speed? and it is lowered because the G-code instructions I mentioned earlier?
The 70% is just the default that pops up when you enable it. It assumes you’ll be changing it so it probably sets it to a super safe, over cooled rather than under cooled, default.
The 70% is not a “max”, it is the actual value the fan will run full time while it’s printing that filament. So make sure you set it to exactly the speed you want that fan to run.
In the PLA profile I use I just set the exhaust fan speed during printing to 10% and left the fan speed after printing to 70%. When printing with this profile the exhaust still blew at 30% during the run, and after the run at 70%. Normally it never blows this hard after a print, so I have the impression that those profile settings are actually overridden by the G-code settings. I’ll experiment a bit more with this.
Hmmm, that’s odd behavior. It should have ran at 10% if that’s what you set it to. I suspect something wasn’t saved or entered correctly. Did you already mess with the gcode settings earlier and not put them back to default?
I always have the after print set to 0% so it shuts down when the print is done. This setting is really only good if you want the chamber cooled down quickly after a print finishes.
I just printed a deflector for the aux fan - so the air blows slightly upwards rather than straight on the bed during first few layers.
Printed today (printer is in my cold outbuilding) and had no issues with warping! Completely flat print!
Because I don’t always remember considering the setting is in filament settings - somewhere I rarely need to go. This way I change nothing and just print as normal.
Same.
No issues with adhesion, but some prints with a large surface area have some very minor warping in the corners. The aux fan deflector (a few minutes to print!) has completely fixed it.
Which aux fan deflector did you print? I have no adhesion issues currently but I’d like to keep it in my back pocket should I run into issues on large prints
Finally decided to go for a deflector as well, for the same reason as @IftiBashir, so i don’t have to (remember to) adjust the settings when its colder. Also, I started to use glue stick for prints i really dont want to fail. Thanks for all your input
I’ve never used glue stick. I even have a bottle of the Bambulab liquid glue - just never used it. I hat the way it leaves all that residue on the plate! lol
