Clogs, Under-Extrusion, and Snapped Filament

Clogs and under-extrusion

• Use a 0.5 mm or larger nozzle. Fibers can bridge across small openings.
• Check for a worn nozzle. If you printed PET-CF with brass, the opening may have worn oversized. Replace it with a hardened nozzle.
• Purge between materials. Leftover lower-temperature plastic can cause partial clogs when you switch to PET-CF, and fibers can stay behind when you switch away. Purge with 3D Clean at PET-CF's printing temperature. See Spotting a partial clog.

Filament snaps in the feed path

PET-CF can break on sharp bends. In testing, it handled a 25 mm bend radius but snapped at 15 mm. Reroute PTFE tubes to avoid tight curves. See Nozzles, hotends, and feeding.

Inconsistent extrusion or banding

If you see regular bands or extrusion that varies along the print, measure the filament diameter in several places. If it's out of tolerance, request help with a possibly defective spool and include the lot number.