Dualnozzle / PLA-CF / Supportmaterial

Bambu Lab H2 Series
1

Good morning everyone,

I’m currently running into a problem with my H2D setup – though I’m not sure if it’s the printer, the filament, or both.

I’m trying to print parts with Bambu PLA-CF as the main material. For the supports, I’ve tested PETG, PETG-CF, PVA, and Bambu Support for PLA. All filaments have been thoroughly dried, so moisture shouldn’t be the issue.

No matter which one I use, I always face the same problem: after the first few layers the supports lose adhesion and start to topple over.

I already tried different support types, infill settings, wall counts, etc., but the result looks nearly identical every time.

For context: these are parts I regularly print (grippers for industrial machines). They all share a similar core geometry, and in the past I’ve always been able to print the supports completely from a single material instead of just the interface layers – which usually makes removal much easier. Unfortunately, for this specific geometry that approach doesn’t work.

If I only use the support material for the interface layers, adhesion is fine – but then I can’t remove them afterwards. So in this case, I must print the supports entirely from PETG (or another material).

I’m aware that Support for PLA isn’t really meant to be printed directly on the build plate (since it hardly sticks there) – I only tried it out of desperation. Unfortunately, the result looked the same as with the other materials.

I’ve attached three timelapse videos that show how the supports fail with the different materials.

Right now I’m out of ideas, because it feels like no matter what I try, the supports just keep failing.

i’ve added the projectfile, i case someone would like to look at the settings

Problemfile.3mf (2,4 MB)

video_2025-09-17_18-32-45-ezgif.com-video-to-webp-converter
video_2025-09-18_21-28-28-ezgif.com-video-to-webp-converter
video_2025-09-22_13-31-39-ezgif.com-video-to-webp-converter

2

Is this a BIQU Frostbite print plate?

You know that it’s only suitable for PLA and PETG, and that both materials require different print bed temperatures (PLA 30-50°C, PETG 50-70°C).

I strongly suspect that’s where your problem lies.

I would try a different print plate and test with higher print bed temperatures.

3

Support interface materials are meant to be printed for interfaces. If you have difficulties to remove it, use the scraper to cut from layer lines.

Or slightly reduced the flow rate of interfaces

4

Yes, that’s correct – but it’s only the Support for PLA that doesn’t stick properly. I’m aware that this material isn’t meant to be printed directly onto the build plate, but I gave it a try anyway. The support base itself adheres fine, so it’s not a bed adhesion issue – the real problem seems to be layer adhesion within the supports.

I also tested with the Bambu textured plate, but it didn’t make any difference. By the way, that plate works great with all other materials I’ve used so far – I’ve successfully printed ABS, ASA, PAHT, etc. on it, and they all adhere really well while also releasing cleanly after printing.

5

Yeah, I know that the support material isn’t meant for printing entire supports – I just gave it a try.

But I also tested PETG and PETG-CF, which aren’t “dedicated” support materials. In theory, those should bond together properly – but I’m still seeing the same adhesion issues.

6

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Your. 3mf

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7

Try to reduce supports print speed

8

i did. in the first post…

9

I would definitely use a Kdavi or Frostbite plate as it will have much better adhesion, that would probably solve your problem. Also have you tried “Tree strong” supports?

10

Post the version that you printed with PETG and PETGCF. I’m surprised that it’s not bonding hard.

In general, your problem comes from that you don’t like the strong adhesion that the Support for PLA provided as a interface material. So you try with other filaments. PETG+PLA of course is gonna be hard to bond well which is why it fails. PVA same thing. In both cases you would need very careful tweaks… which I don’t like so I just use Support for PLA and then pry it open with the scrapper blade, or any sharp knife. Works very very well for me. I know the bonding might be too strong to just snap off, but that’s the most stable result I can get.

Support for PLA/PETG on the other hand, provided slightly too little adhesion for PLA, so I don’t use it for PLA.

One tricky thing with different material support printing is that due to the difference of support vs part shrinkage rate, you might have a deformed support. Which is why unless you print very slowly, or use all CF materials (not petg+petgcf, but petgcf+petgcf), otherwise you might always have trees that are… “unexpectedly too high”.