Strange pattern on 1st layer, stripes perpendicular to nozzle movement
thanks for looking at my request for help. I have my i3 Mk3S for almost a year and have printed in the order of 200-300 hours. So far I have been almost perfectly satisfied, only the linear bearings in the X-axis got worn our (or dry) and caused crash detection. First I took them appart and lubricated them, but finally I have replaced them with IGUS bearings which am really happy with.
But here is my questions: For some weeks I have an effect which I have not been able pin down. When I print bigger parts and watch the first layer printing, I see a well visible pattern on stripes which run almost perfectly perpendicular to the nozzles movement direction. When I pay close attention, I can also hear some light clicks when nozzle moves, painting these stripes.
That pattern was one of the reasons to go change to the IGUS bearings in the X-axis, as I had suspected that the linear ball bearings would once again cause some troubles. I have tightened the tension of the X-axis belt and tested if the Y-axis moves smoothly, which it does.
In the picture I have used clear PETG, which is not that good to see on the print bed, but the stripes are pretty obvious. I tend to believe that I have seen little steps in the edge from the already PETG covered area of the part and the print bed surface. But that is only possible to see with very light material against the dark print bed.
Does anyone have any idea what I could try next? Should I replace the Y-axis bearings, despite the fact that they move like a dream? Do I need to tighten the Y-axis belt? Or could this be an extruder issue, meaning that the filament is not evenly pushed into the hot-end?
Again, any idea is welcome. Of course I would update this request once we have figured out together where this effect comes from.
Thanks in advance folks,