PETG Quality Issues

Bambu Lab H2 Series
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Hello. I am having issues with print quality while printing with PETG. My object that i am trying to create is somewhat complex, so i am not sure if that is my issue or not.

As you can see in the images, I am getting a “dull” color around the inside edge of the print. The object i am printing is paused approximately 1/2 way through the print, and a rubber piece (TPU) is set into the print. The printer then proceeds to print over the rubber insert, leaving some of it exposed on the inside. The printer thinks the inner edge is a cantilever, but it technically isnt because I am pausing the print and inserting the rubber piece.

H2D printer, Sunlu PETG filament, .4 nozzle, .16 layer height, all standard bambu studio settings.

I thought maybe this was a nozzle temp issue, but im not sure if that is correct. Any help would be appreciated

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I think you answered your own question - the printer thinks the inner edge is an overhang and it’s printing it that way. So slower feed rate and maximum fan cooling. It shouldn’t be surprising that the material looks different under those conditions.

You can verify that’s what is going on with some test prints that “force” overhang printing, which would have the same visual differences as what you’re seeing if that’s what is happening.

As for how to avoid it, you may want to manually edit your Gcode to remove the cooling fan command in that section, and potentially crank up the print speed for that section as well. I suspect the printer profile may also have some settings that allow you to change overhang behavior as well.