PETG HF - Strange Finish

Bambu Lab H2 Series Bambu Lab H2C
1

I’ve had my H2C for less than a week now and have put 50+ hours of print time in. Mostly with a good bit of PLA and almost a whole roll of PETG translucent (all Bambu lab filament.) Today I tried printing with some PETG HF for the first time and I noticed a strange surface finish while printing. The surface was matte looking and rough when touched. The weird thing is that I turned up the speed to ludicrous and the print immediately smoothed out and had a much better finish. I’ve been using only the default Bambu profiles for each filament. What’s going on here?

For the record, I have a fair amount of 3D printing experience, several years, but I’ve never seen an issue like this.

See the photo below. The top left corner where the print gets darker and smoother is the area printed after I’d turned up the speed.

IMG_4033
IMG_4033640×480 123 KB

2

The standard question: Did you dry it after unboxing? Many PETGs print fine without extra drying, but BBL PETG HF definitely needs it when it comes out of the box. Maybe higher speed means worse melting / lower temperature (less time in the nozzle) and therefore less bubbles from the moisture?

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3

Makes sense, will dry it and try again. Thanks for the suggestion. :slight_smile:

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4

I had same issue on A1 but it was because I didn’t dry it

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5

Thanks, I dried it and it works great now.

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6

your welcome happy to help!