Layer-drift problem solved
This article was published Jun 20, 2019.
Had a few days with serious layer-drifting again. Normally when this happens your belts are not tighten enough, but mine are, so got a bit puzzled until I realized the filament was tangled on it´s way from the spool to the printer head, also my new spool holder was not moving as freely as it should. After changed back to my previous spool holder and re-drawn the filament all the way once more, that problem was fixed. Also low infill procent can be a problem cause it makes the print head to sick-sack during printing, which can itself make these problems. If you design your own models, avoid thick walls and use 100% infill.
Maybe good to know if you end up with the same problem.
See left model, it is printed with 18% infill normal speed and with the filament tangle problem. Right is 100% infill, 75% normal speed and filament feed problem fixed.