Strange artifacts in holes when printing PETG

[Mechatron127 1]

Hi,

 

I have started printing with PETG a while ago and had a lot of issues with the printer I bought for that. Overextrusion, play on the X- and Y-axis wrong bed leveling but all that seems to be solved now.

 

In a print that is currently being printed I noticed a strange buildup of material in one of the eight 4mm holes, see picture. The 4mm hole is below the 11,5mm hole that has a very descent quality. Further to the right is another 4mm hole that is good. Yesterday this also happened in another print on a different location of the bed, different brand filament also.

This grey filament is from PolyMaker, the filament from the other print is Jupiter, that is the house brand of the store I buy most of my printing supplies (123-3D print).

 

Does anybody know what can cause this issue? It seems like a very local adhesion issue to me. Is this a known thing, I call it a fatty hole because it looks a bit greasy.

 

In this case it is not a real issue functionally, at that position the part is mainly a spacer, so I will continue the print, had it been the hole on the right it would have been a real issue and the print would have had to be aborted.

 

Background info, the nozzle is dirty bco all the tries and overextrusion from the past. Only thing I can think of now is that there is some gunk from that deposited on this location causing bad adhesion and causing the following (next layers) issues but that is a guess, after this print I will either clean the outside of the nozzle or replace just to be sure.

 

Kr,

 

Leo