What causes this wavy pattern on thinner walls?

[mattanonymous]

I've seen this with ABS, PLA, and now PETG. I've tried changing the temp, but it still happens. I have a Makerfarm I3V 10" with the hexagon hotend. It seems like it only happens on thinner walled areas, so I created a simple test object and, sure enough, an entire side is patterned that way. The other sides had a little of the pattern, but not much. The opposite side has some diagonal banding I've been seeing on a lot of prints too.
http://imgur.com/a/U3RIw
Any ideas?
Thanks in advance, Matt

[dustmann]

I would venture a guess and say that your bed is not perfectly level, and your nozzle is slightly too high from the build surface on the wavy side. Try adjusting your end-stops, or you can try adjusting your z-offset in your slicer software to lower the nozzle slightly and see if it goes away. Also, check your extruder motor, it isn't skipping steps by any chance is it?

The second photo is intriguing though with the spiral banding.. a setting in your slicer maybe? Do you have the vase mode enabled?

[mattanonymous]

I finally got the printer back together and managed to solve the problem by turning off "Detect thin walls" in slic3r. Still no idea about the banding. Spiral vase is not checked.