Problems with large part dense layers (PLA)

[knightschneider]

I tried to print a large cube 20 x 20 x 20 cm but allready on the dense groundlayer (first layer is ok, but the 4 others look rippled (see picture). Am I overextruding?

I use slic3r (layer height 0.4 mm, 195 °C extrusion temp, infill print speed 50 mm/s)

material: black PLA, 1.75 mm filament

[wirlybird]

This can happen when the nozzle is to close for the first layer. Also if you are using a .4 nozzle then your layer height is to much.