Neptune 4 Max Scrubbing?

[galaxybeing]

I bought this printer new about 9 months ago or so and have made q number of nice things on it. But I've always thought it sounded like the tip was scrubbing the print as it zig-zags back and forth doing infill, but never really gave it a lot of thought, since everything turns out OK. Up till now I've always used PLA, But recently I bought a couple rolls of PETG, having never used any. Today I was printing this back cover to something at about 35% infill and using PETG, and had to stop. It was REALLY scrubbing. So bad it was making all these crumbs everywhere. After about 3 hours I noticed it looked like the filament supply spool wasn't turning, but the print head was still zooming back and forth as if it was printing. What apparently happened was all these crumbs had caked up so bad on the print head, it wasn't feeding. So I stopped the print and re-worked my Cura file for PLA and put a roll of PLA on the machine. Apparently it didn't hurt anything because it's printing away as we speak. Questions: Why does this machine scrub the print as it runs, and what are all these PETG crumbs everywhere? Thank you.

[Bikeracer2020]

Could be you had a clogged nozzle and the crumbs you see are from the filament grinding, Check for clogged extruder gear and try a new nozzle.

[galaxybeing]

Where did the second picture I posted go? That was the one hat showed the problem. I know I posted it because I checked afterwards. Weird.