Thank you for your replies.
It does the same with 100% or less infill. With less than the grid is also these wisps, see photo.
It sais "Ultimaker 2 Go", not "pro", sorry.
The material is plastic? I'm not known with the component of the printers, I just know a little bit how to use them. It is not my printer, I just use it. I don't know what nozzle, sorry.
I have done the same thing with a other printer in the past, ant that worked fine, now I use this one and it doesn't work.
I first make the model in SketchUp, than open that in CURA and make it a gcode. See attachments.
I do not know if this printer has worked ok in the past. This does however now happen to all prints I try with this printer.
What I have tried is changing settings in CURA, like Wall Thickness, Top and Bottom Thickness, Infill ofcourse, Speed.
I have not changed anything in "Dual Extrusion", those settings seem to complicated for me.
Does someone recognize this and knows what I have to change?
UM2GO_schakelaar alles v2.gcode
schakelaar alles v2.stl