White PETG HF flow calibration on H2S

Bambu Lab H2 Series Troubleshooting
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I think this might be a bug with the H2S profile of this specific filament, but before I report, I thought I’d first share here to see if anyone else has information or thoughts.

I have a few different colors of PETG HF loaded into AMS 2 Pro, all dried together for 12h @65c by the AMS and print very well with default profiles on H2S. However, the white PETG HF has a rough surface finish, with inconsistent extrusion showing in layer lines, and some underextrusion in first layer.

The reason I think it might be flow calibration is that it takes a bit longer for it during flow calibration, and also there is no consistent under or over extrusion problem, rather a combination of both which shows on surface quality.

There is no stringing or clumping, mainly just extrusion inconsistencies and only with the white color on H2S.

Has anyone used this color or seen a similar issue? Filament was purchased in the past month.

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I have been printing White PETG HF and have not seen your issue.

I presume the filament is having a rough surface finish. You might want to measure the thickness of the filament and check if that is consistent. If that is not the case, that could be a reason for the flow calibration to take longer because of the inconsistent results during measurement.

Did you get your White PETG HF before or after the long “Out of Stock” period?

I still believe there has been a quality issue and that has been the reason for the shortage of PETG HF.

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That is a good point. I bought this on 27th of Aug. I believe right after it came back in stock, and it is the spooled version.
I checked the thickness for about a 30cm length and it appears spot on with about a 0.02 variance, same as the black one that I have in the AMS.

Could it possibly need more drying? may I ask how long/what method you dried yours?

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I would say your filament dimensions are fine. And buying it after suggests, your filament is from the new batch.

I normally don’t dry my PLA and PETG filaments a lot, since generally we don’t have a very high humidity here in the Netherlands.

But when I do, a normal drying cycle of 12 hrs is sufficient.

It never hurts to dry it a bit more. Moisture could be the reason of your issue.

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Do you have photos? Upload the photos, videos, 3mf files… to help diagnosing!

Also, I noticed that for some bambu filaments the default bambu profile doesn’t work. E.g., PLA Matte, even though the filament dimensions are correct (also having a 0.02mm variance but totally acceptable)