CPE Accumulates on Nozzle

[jakepoz 2]

Hey, been printing on an Ultimaker 2+ with CPE lately. I noticed that plastic tends to accumulate on the nozzle tip, and eventually this falls off onto the part that's being printed, leaving an ugly scar or burn mark. Every part I print has a couple places where black, carbonized CPE has brushed off from the nozzle and gotten embedded in the part. 

 

Seems to happen with Ultimaker CPE (Red), Ultimaker CPE+ (clear), as well as MatterHackers PETG (Red). I have been using default settings from Cura 3.5.

 

I never had this issue with PLA, parts were always beautiful.

 

Does anyone have any ideas?

[geert_2 557]

I have this with PET too (non Ultimaker - ICE). These materials seem to be much stickier and more rubber-like than PLA when molten. PLA is more like yoghurt, PET goes a bit in the direction of chewing gum.

 

For my PET material, printing slow and cool reduces the effect, but does not totally eliminate it.

 

[Smithy 1,144]

In my opinion, PETG is terrible to print. I had a lot of surface quality issues with CPE and got better results with Colorfabb XT. Another one hat bad luck with XT and got better results with CPE.

 

In this thread you find some more infos and test results with some tips at the end: