Found this thread as I’m experiencing exactly the same issue. Although there is very minor z-banding on smooth featureless walls, it’s far worse when there are holes or depressions which cause these horizontal ghosting bands.
I’ve literally tried everything already mentioned in this thread including the infill/wall overlap from the default 15% in increments all the way down to -5%.
Nothing makes it worse or better. AP and flow calibrations both automatic and manual with different values circling around the apparent manual optimals. Different speeds down to very slow. Different numbers of walls. Different infill, inner wall, and outer wall ordering.
Belt tensioning. z-rod vertical free play check (none at all).
Brand new hot end and extruder. No difference.
Different filament types, temperatures, etc.
Hundreds of test prints. Nothing changes it. The sad thing is I have a 6 year old QidiTech one-x that prints the test cube with the hole through the center perfectly but my brand new x1 carbon looks like craps.
Tech support has been making suggestions of different thing to try but nothing has worked.
What’s very strange, as you said, is that every time I change a parameter, the problem doesn’t get better or worse. It’s a very strange constant… problem.
That sentence summarizes my own experience with the P1s.
I use (rather wanted to use) the machine for prototyping technical parts. Adding features during a design iteration throws completely unrelated features out of the previously checked dimensions.
Even placing separate parts next to each other can influence the dimension when printing ‘by layer’. I encountered an incidence where placing a cylindrical part next to a basically square shaped part lead to a curved wall!
Another quirk is that cylindrical prints (on xy plane) are repeatably and spot on 0.2mm smaller than square parts with the same dimension.
In summary the machine seems completely inadequate for mechanical prototyping. I bought it because of ‘fast’ & ‘hassle free’ but the time it saves me in printing is lost in having to triple the amount of iterations till the printed part is dimensionally in tolerance.
Sadly I’m back to my old marlin bed slinger for now. For one-offs I get the job done faster and with less cussing.
There are months old threads in the forum indicating all these issues separately and no solutions.
I haven’t had the time do dive into seriously analyzing the problem. But to me, it seems to be a firmware issue regarding the motion planer and path smoothing tolerance.
With the support muppets and canned replies in the way of getting in dialog with an actual engineer I’m a bit hopeless that this will get resolved any time soon…
I too wondered if it was firmware but then you have @walidezza saying he and his brother have the same printer with the same firmware version and his brothers prints are perfect and his aren’t when comparing the exact same files.
I also have this problem. I’ve reduced the flow rate and infill-wall overlap and got slightly better looking outer walls but there is still banding/ghosting right after a hole or feature.