xDmSx

Thank you, @burtoogle. That thing worked. And now pipe came out with acceptable quality without much holes in shell 😊, just needs some little tweaks. Additional movement over inner wall was removed. Haven't notice these parameter before. But my original problem was jerky movement on inner wall and it still remains, but not produce major impact on print quality now. So I will leave it as it is for now.

I think under-extruded lines happens in my "ring bench" because of pressure drop and leaking of some filament during strange move nozzle make above already printed inner wall area. If I set Z-seam to be at one position (not random) it can be clearly seen. Under-extruded lines right at outer wall start, not at layer change! I have 0.6mm nozzle, and ring wall is 1.8mm. Cura 3.6. Same with version 4.0. Look at simulation video. You can see nozzle moves around green line 2 times - 1 when printing and 1 when travel to start of outer (red) wall! But speed is same, not as travel (I can see it while printing), so is it not a travel move? Whichever settings I change I can't get rid of this useless move. e.g. Combing, Line Width, Do not print thin walls etc.

I don't know why under-extrusion occurs. Now I just wondering why inner wall prints with noticeable stutter, while outer walls smoothly with same speed-accel-jerk settings.

I don't know if Cura is to blame (so topic might not be relevant). Downloaded CraftWare and it produced similar result (Have not much experience with it) . But Slic3r still make no problems. Just can't understand why outer walls are fine and inner stutter even with same speed-acceleration settings. I uploaded some different project. It has same speeds for walls, but still stutter near smaller radius. EllipseBench v1.3mf EllipseBench v1.gcode

Cura generated g-code produce stuttering on inner walls of cylinder with 3 perimeter walls. No stuttering in Slic3r with same parameters. Wall order optimization have no impact. Linear and less curvy objects don't have this problem objects. Printer: Anet A6 (TATARA frame) Video #1 Video #2