Hello gr5,
thank you for the detailed reply.
I lowered the nozzle a bit like you suggested and got better results. Still some gaps however depsite being really close and the top layer looks the same.
I suspected that I have an underextrusion issue as well.
To check that, I printed a hollow cube in vase mode. So there is only one wall which should be 0.4mm thick. At 101% flow rate, I got to almost exactly 0.4mm. The caliper is a factory calibrated Mitutoyo, so it should be precise.
Also, as you can see in the overview image, the nozzle impacts the already printed first layer (0.15mm) quite severly. So that should be an indication that too much material is deposited or the nozzle is to close.
The too point above indicate that it is not an underextrusion issue. Or do you think it still could be underextrusion despite that?
What I also do not get: If it is underextruision, why only in one direction?
The volume I am extruding is 3mm³/s, on the initial layer and top skin even 1,5mm³/s.
I uploaded a picture of the top layer and also the first layer after infill as well.
The top layer is actually printed with 110% flow rate.
I found it interesting that on the first layer after infill, what looks like 8 lines are actually only 4 (watched closely during printing). The start and endpoint of the bridges do not seem to be aligned somehow.
Printing Material is FormFutura PLA at 205°C.