Black marks on rear lower idlers only

Bambu Lab H2 Series
1

I’m in the middle of a print, but noticed these black marks/smudges on the rear lower idlers. Anyone else have these? There are a few smudges/smears on both

How the heck do I get back there to clean/inspect them with my big head and sausage fingers? LOL

I don’t see any visible wear on the belts, only 92 hours of printing so far. Getting as good or better quality than my P1S reprinting some items for sake of pla contamination in my petg causing brittleness in some prints previously.

PXL_20250911_215456938~2
PXL_20250911_215456938~21920×2291 91.1 KB

2

I got that too on the same exact one. After reading the thread about little black rubber pieces falling from the belt being normal, I’m assuming this is probably normal too.

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3

This is normal, over time it’ll stop happening.

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4

You can clean it with a Q-tip and a little IPA. Have the printer powered OFF and hold the Q-tip against the pulley while you slowly move the print head around to make the pulley turn.

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