Defects on the top layer

[Ragnor 0]

Hello all,

During a recent few prints, I've been noticing defects on the top layer. The rest of the print goes absolutely fine, but there's these oddities on the top and I've got absolutely no idea what could be causing it.

I've checked the troubleshooting guide very thoroughly and noticed the surface scratching there, but this is still a different issue I believe.

Can anyone help point me in the right direction to fix this? I've been thinking filament defects or thickness variation, but it would be a strange coincidence to have 7 defects on the top layer, but none on any of the lower layer top surfaces which cover at least as much area.

Thank you for your time.

[neotko 1,417]

Apart of the scratch, zooming it on that top layers there seems to be underextrusion.

What material is? What fan settings ocurred? Also there's a possibility that the underextrusion occurred later from some bite on the filament reaching the hotend (so underextrusion).

Please share more details. Also check the filament inside the bowden for bites from the extruder just in case.

[DidierKlein 729]

How many top layers do you have? It might also be that you don't have enough layers and that covering the infill correctly is not possible everywhere?