Issues with walls

[morpheus1978]

Hello! How about people from the forum? I consult them, maybe someone with more experience can help me with the problem I am having.
For some reason when trying to print certain pieces, I do not make a single wall, but two walls with a groove in the middle, I attach a photo.
I already tried the recommendations of the quality problem section, without being able to solve it.
The walls that I use in the design have some 1mm and another 1.65mm.

[MotoGP1199]

I'm assuming the wall thickness in the STL is set to slightly larger than two diameters of your nozzle (IE nozzle set to .48 and the wall thickness is 1.2). So it makes the object wider to allow it to be the right thickness but can fill in the center. You can try turning on in the ADVANCED tab "Internal Thin Wall Type" and setting it to "allow gap Fill", that might help.

[dkightley]

Allow me to disagree with the previous poster.

Setting the Internal Thin Wall Type to "Allow single extrusion fill" will allow just that...a single extrusion in between the perimeters of the wall. But you need to set the Allowed perimeter Overlap to a value large enough to allow the three fixed width extrusions to fit in the overall wall thickness.

[nimmy12]

Hello, Any ideas on how I can fix this, My brother has just started doing this and I'm not sure why the bottom layers always within the first 1cm. I suspect subtle layer shifting.