Failed Print Core

[inworks 0]

Hello All.

 

We were recently printing MatteraHackers PLA on an Ultimaker 3 Extended with Cura's recommended "Extra-Fine" setting. The first layer looked as expected, but the print core began to slowly under-extrude, and eventually no material was coming out of the nozzle. The support PVA was being printed without issues. I later found some of the PLA filament appeared to be "swollen" high in the print core, preventing it from being pushed through.

 

I swapped the print core for another AA 0.4 core we had around and the print finished successfully. Clearly there was a problem with the old core. Was it some how "back-heating" onto the filament, causing it to swell and get stuck? This was a print core that we have been using often for about a year. Do the print cores wear out and need replacing? I don't see any recommendations, by Ultimaker, for replacing print cores as part of regular maintenance.

 

Thanks for any tips you can give.

[fbrc8-erin 296]

Hi, Inworks,

 

Normally the heat creep/swollen filament issue is usually related to the front fan. Can you confirm that the front fan is running?

 

The front fan's purpose is to keep that upper part of your print cores cool. If it's not running, the filament is going to swell due to heat expansion. Are there any filament hairs visible around the fan? It can cause it not to spin.