The secret to printing PA-CF

[TheDullCarbide 0]

I've been having that dreaded clogging while printing Colorfabb PA-CF. I have a 0.4mm hardened nozzle in an E3D V5 head, printing with 0.2mm layers. I found somebody in Reddit who hit the nail on the head. He said that when the extruder retracts, the fibers that were inside the 0.4mm hole stick to the end of the filament as it pulls back. Then when the extruder primes again, those fibers don't always re-align with the 0.4mm hole and sit on top of it sideways, clogging it. Now if this happened with an unfilled filament, that sort-of tail would just remelt in the nozzle. Since the carbon fiber doesn't melt, it just clogs the hole.

 

The guy on Reddit said that the key is to keep the filament moving forward. I tried this by turning off retractions and only using combing (even though Colorfabb says it can handle retractions) and I've done multiple >3h prints now without clogging. Also, being this filament is so hard, it handles very well without retractions and leaves very minimal stringing.

 

I hope this helps you as much as it helped me. Now if only I could afford another spool...

 

EDIT: Just realized this was posted in the completely wrong section. I reposted it in the materials section now. If an administrator wants to delete this, please do.

Edited January 1, 2019 by TheDullCarbide